Victor Martinez may and on the 15-day disabled list due to his fractured left thumb tip.

The Red Sox offered an update regarding the medical exams of injured players Dustin Pedroia, Victor Martinez and Clay Buchholz. The short-hand:

–Pedroia won’t need surgery or the placement of a pin on his non-displaced navicular fracture in his left foot. As WEEI.com reported, he is expected to be sidelined for four to six weeks.

–Martinez has what the Sox describe as a “minimally displaced fracture on the tip of his left thumb.” He won’t need surgery, but while the Sox won’t place him on the disabled list on Monday, they have also not ruled out a DL stint.

–Buchholz was diagnosed with a left hamstring strain (a modification of the hyperextended knee with which he was diagnosed on Saturday). The Sox don’t plan to place him on the DL. He’s not scheduled to pitch this week.

Here is the full press release with details of those exams, as well as roster moves involving Eric Patterson, Fabio Castro and Boof Bonser.

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After undergoing an MRI earlier today, Clay Buchholz has been diagnosed with a left hamstring strain. He is not scheduled to start this week at Fenway Park, but there are no plans to place him on the disabled list. Buchholz suffered the injury running the bases in the top of the second inning during his start on Saturday in San Francisco.

Dustin Pedroia was examined by Red Sox Medical Director Dr. Thomas Gill who confirmed that he has a non-displaced fracture of the medial navicular bone in his left foot. Pedroia was placed on the 15-day disabled list on Saturday after suffering the injury Friday night in San Francisco when he fouled a ball off his left foot in the top of the third inning. He is not expected to require surgery. The usual timetable for this injury is approximately six weeks to return to play.

Victor Martinez also underwent further examination which revealed a minimally displaced fracture on the tip of his left thumb. He is also not expected to require surgery. Martinez left yesterday’s game in San Francisco after the third inning due to the injury which was sustained after having two foul balls hit off his thumb while he was behind the plate. There will be no roster move today regarding Martinez.

ROSTER MOVE: The Boston Red Sox today added infielder/outfielder Eric Patterson to the active Major League roster and designated left-handed pitcher Fabio Castro for assignment. Patterson, who was acquired from Oakland on Saturday (June 26) in exchange for minor league left-handed pitcher Fabian Williamson, will be available for tomorrow night’s game against the Tampa Bay Rays at Fenway Park, wearing No. 3. The announcement was made by Executive Vice President/General Manager Theo Epstein.

Patterson has appeared in 45 games for the A’s this season, batting .204 (21-for-103) with five doubles, two triples, four home runs, nine RBI, 13 runs and six stolen bases. He’s played in 25 games (22 starts) in left field, seven (two starts) in center field and five (one start) at second base, committing just one error overall for a .985 combined fielding percentage at the three positions.

Castro was recalled Friday (June 25) for his second stint with the Red Sox this season, but has not appeared in a game with the club in 2010. The left-hander has made 17 appearances (five starts) for Triple-A Pawtucket this year, going 3-5 with a 6.65 ERA (32 ER/43.1 IP), 36 strikeouts and 22 walks.

BONSER CLEARS WAIVERS: Right-handed pitcher Boof Bonser today cleared outright waivers and has chosen to become a free agent. Bonser was designated for assignment on June 18. He did not record a decision while posting an 18.00 ERA (4 ER/2.0 IP) over two relief appearances with the Red Sox in 2010.

In order to make a roster spot for 22-year-old southpaw Felix Doubront, the Red Sox designated pitcher Boof Bonser for assignment on Friday. The team now has 10 days to trade or release Bonser, who was acquired in the offseason from the Twins but has spent considerable time on the disabled list. The 28-year-old made just two appearances for the Sox, allowing four earned runs in two innings.

Manager Terry Francona said Bonser was the odd man out because they wanted a second left-handed reliever behind Hideki Okajima. That meant keeping Dustin Richardson, who has allowed a hit but hasn’t been charged with a run in 2/3 of an inning.

“We really like having a second lefty. Part of keeping Oki productive with one lefty that’s a pretty good lefty, you can overuse him. We don’t want to overuse guys,” said Francona. “Richardson has done a really good job in Triple-A. We’d kind of like to watch him pitch a little bit.”

Francona suggested that the team decided to keep Scott Atchison over Bonser because the former is in a position where he can pitch fairly regularly. Bonser, who is 16 months removed from shoulder surgery, required greater restrictions on his workload. That said, based on the velocity that Bonser has shown (he hit 95 mph in a minor league relief outing), Francona suggested that the right-hander is “pretty healthy” and that he would likely resurface again soon.

“Boof’s going to pitch in the big leagues,” said Francona. “I believe that.”

BALTIMORE — Red Sox pitching Boof Bonser‘s fastball registered at 95 mph in his inning of relief on Saturday night with Triple-A Pawtucket, according to manager Terry Francona. The relief outing was the first by Bonser in his 30-day rehab assignment, which concluded on Saturday with his perfect inning (2 groundouts and a lineout).

“He threw the ball really well,” said Francona. “[His velocity] played up for that inning, which we expected.”

Bonser has been returned to the Red Sox from his rehab assignment. There is no official date by which he must be activated from the disabled list, but it would appear likely that the Sox will activate him in the coming days. Bonser has a 6.34 ERA in nine rehab games with Triple-A Pawtucket this year, but he allowed just one run in his final three appearances, spanning 14 innings.

Jacoby Ellsbury

Red Sox outfielder Jacoby Ellsbury started his minor-league rehab assignment by going 1-for-3 with a single, walk, RBI, and two runs while hitting leadoff and serving as the designated hitter for the Triple-A PawSox on Monday.

After a pair of three-pitch groundouts (one to second, one to short) in his first two plate appearances, Ellsbury delivered an RBI single on the first pitch of his third at-bat to drive in a run in the bottom of the sixth inning. Ellsbury advanced to third on an error by Syracuse left fielder Leonard Davis, then scored on a sac fly.

Each of Ellsbury’s first three at-bats came against right-handed Chiefs starter J.D. Martin. Syracuse summoned left-handed reliever Atahualpa Severino to face Ellsbury in the seventh inning. Ellsbury took all six pitches that Severino threw en route to a full-pitch walk, and then scored easily on Josh Reddick’s two-run triple.

Monday’s game marked Ellsbury’s first since April 11, when he collided with third baseman Adrian Beltre while chasing a foul ball. Beltre’s knee hit Ellsbury in the chest, resulting in a small fracture of the ribs. The Sox are 16-16 since then, and have averaged 5.0 runs per game (sixth in the majors). Through the first six games of the season, Ellsbury was hitting .333 with an .800 OPS and two steals.

Ellsbury is now scheduled to head to Portland on Tuesday to continue his rehab assignment.

Also of note in Monday’s PawSox contest, Boof Bonser made his third rehab appearance since returning to the PawSox after being sidelined by shoulder tightness. Bonser lasted 4.1 innings (his longest rehab outing to date), permitting two runs on five hits and three walks while striking out three. In three starts for Pawtucket this month, Bonser now has a 3.18 ERA.

Red Sox pitcher Boof Bonser got shelled in his second rehab outing for Triple-A Pawtucket, allowing nine runs in two innings. He allowed five hits (including a homer), three walks and hit a batter, throwing just 22 of his 47 pitches for strikes.

After the performance, Bonser told reporters that he experienced shoulder stiffness that worsened both by virtue of cool weather and a long top of bottom of the first inning by his team.

“The thing seized up on me and all heck broke loose,” Bonser told reporters. “When you only go two innings and your shoulder feels like crap, especially coming off surgery, it’s not a great day. Put it that way.”

Bonser missed all of 2009 after undergoing surgery on his rotator cuff and labrum. The Sox acquired him from the Twins in a trade for minor league pitcher Chris Province in December.

With Opening Day now less than a week away, the roster decisions are crystallizing. The biggest variable in determining who will be ready to play in the majors come April 4 is health, as the Red Sox try to wade through who is in position to help the big league club for the start of the season and who will need additional work.

Arguably, the decision is more complex with Mike Lowell than it is with any other member of the club. Even the player had little opinion about whether — after entering last night’s game against the Rays with just 10 plate appearances this spring — he would be ready at the start of the year, though he did note that his status as a reserve could diminish the gravitas of that determination.

“I don’t know what they think are quality at-bats. Maybe yes, maybe no. I honestly have no idea. I don’t know what they feel is adequate or not. It’s the organization’s call, not mine,” Lowell said. “To go to Boston to not play? Same thing, right? If I go it’s not like I’m going to play right away and if I don’t go it’s not like I’m not going to play right away. I’m not playing either way, so it’s all up to them.”

For more on Lowell’s uncertainty about his future, click here.

– Josh Beckett has no such questions about where he’ll be on Opening Day: he’ll be starting the first game of the season for the Sox for the second straight year. The picture is slightly less clear for Opening Day in 2011, since Beckett is a free agent after this year. After a strong final spring tuneup against the Rays, he still had little to say about contract negotiations with the club, amidst reports that the Sox were unwilling to offer him a deal of more than four years.

– Daisuke Matsuzaka knows that he won’t be pitching the Red Sox’ season opener. But he could be taking the mound at McCoy Stadium as the Opening Day pitcher for the PawSox this year. He threw a 62-pitch simulated outing on Monday, striking out seven of the 15 Red Sox Single-A hitters he faced, and he will next pitch on Saturday, following Tim Wakefield to the mound in an exhibition game in Washington, DC. Pitching coach John Farrell suggested that Matsuzaka is showing steady improvement in his spring outings. His fastball was 89-91 mph on Monday.

– The back of the Sox’ Opening Day bullpen took little definition, aside from the revelation that Boof Bonser likely won’t be ready to be a part of it. Bonser, like Matsuzaka, threw a simulated outing on Monday, and he will not travel with the Sox to Washington on Saturday, instead remaining in Fort Myers to throw a minor league game. While he was slowed somewhat by groin stiffness last week, Farrell pointed out that the right-hander is also still in the early stages of rebuilding arm strength after undergoing surgery on his right shoulder 13 months ago.

Meanwhile, both Scott Schoeneweis and Alan Embree had poor outings on Monday night against the Rays, and Joe Nelson issued a walk in his third of an inning. Manny Delcarmen, meanwhile, continues to work through his delivery issues that have diminished the power that he generates on the mound, as he joined Matsuzaka and Bonser at the Sox’ minor league training facility on Monday.

– Junichi Tazawa was not expected to help the Sox on Opening Day, but he did represent one of the Sox’ primary Triple-A depth options should a starter be needed. However, Tazawa may not be available for such a role for some time, pending the outcome of his visit to Dr. James Andrews in Birmingham. He has been dealing with tightness in his elbow since last season, according to Farrell, resulting in the visit to Alabama. Scouts this spring had wondered about Tazawa’s diminished velocity and inability to work effectively down in the strike zone.

-- Fenway Park will make the Opening Day roster, and Red Sox CEO Larry Lucchino detailed the upgrades to the 98-year-old ballpark on Monday. Of course, Lucchino seemed somewhat caught off guard upon finding out that one fan’s seats may have been moved to a less desirable position following the renovations. That fan? Mayor Thomas Menino.

FORT MYERS, Fla. — It was a busy day of baseball for the Red Sox, with the team flung all over Florida.

The most promising development for the big league club actually took place at the minor league complex, where John Lackey was dealing for five innings. Despite allowing a solo homer to left by Daniel Nava (the only run Lackey has allowed all spring), the big right-hander featured a nice arsenal of swing-and-miss pitches, including his sharpest slider of spring training. Of the 15 outs he recorded, seven were on strikeouts, and six were on grounders. He was particularly pleased with the fact that he hasn’t walked a batter this spring, suggesting that steering clear of free passes was an important component of success in the AL East.

The Grapefruit League action did not go quite so swimmingly. Most notably, Boof Bonser had a rough day both physically and in his line score. After a sharp 1-2-3 first inning, he gave up homers in both the second and third innings, and finished with a yield of five runs on six hits and two walks (with two strikeouts) in 2.0 innings (he allowed all three batters he faced in the third to reach).

According to manager Terry Francona, Bonser said after he left the game that he felt discomfort in his right groin.

“We hope it’s certainly not much,” said Francona.

Bonser, however, did not mention injuries in dissecting his poor performance.

“It was very frustrating, you know, to try to come in and get that last spot and go out and do something like that, that’s not fun at all. That takes its toll a little bit,” said Bonser. “They say one step forward and two steps back. I think I got my two steps back today.”

Francona, however, suggested that the Sox weren’t going to “penalize someone for two bad days.” He said that the team has been pleased with Bonser’s delivery and arm action, which they consider more significant than his 11.57 ERA.

The Rays continued to pound Sox pitching after Bonser left the game. For his second straight game against the Rays, Junichi Tazawa showed that he can get pounded if he leaves his pitches up in the strike zone. He allowed three homers, and both Scott Atchison and Joe Nelson – each of whom is competing for a spot in the Red Sox bullpen — allowed one.

“Those boys are real comfortable at the plate,” said Bonser. “I don’t want to say it but they need to get uncomfortable real quick.”

– Michael Bowden and a group of relatively obscure Red Sox pitchers fared little better against the Cardinals, losing 13-8. Bowden allowed four runs (three earned) in three innings on six hits. Still, the Sox were ahead, 7-6, entering the bottom of the eighth before St. Louis unloaded on Ramon A. Ramirez and T.J. Large for seven runs in a 13-8 win. Of some note was the fact that Bill Hall — trying to reacclimate to shortstop — committed a pair of errors at the position.

– Alan Embree threw a bullpen session, and will throw a minor league game later in the week.

– The Sox were trailing the Rays, 11-1, entering the bottom of the seventh. The team then erupted for eight runs in the next three innings, but with runners on second and third and two outs in the bottom of the ninth, highly regarded prospect Derrik Gibson had a comebacker to end the game in an 11-9 loss. Noteworthy in the comeback bid: Mark Wagner, who entered the game in the bottom of the seventh, launched a pair of triples. Wagner hadn’t hit a triple in a regular season game since 2007, when he was with Hi-A Lancaster.

Since 1920, only 64 big league catchers have hit multiple triples in a game. John Buck did so for the Royals last year, becoming the first catcher to accomplish the rare double since 2000. Here’s the list.