In some respects, the outcome of the game represented a secondary concern for the Red Sox on Friday.

In the top of the fifth inning, Daisuke Matsuzaka — who had allowed all of four hits over a 19-inning span that was in its third start — threw an 87 mph fastball that Ichiro Suzuki grounded back up the middle for a hit. There were two oddities at work: first, that Matsuzaka had thrown his fifth straight 86-88 mph fastball; and second, Matsuzaka made no effort to make a play on the ball.

Catcher Jason Varitek immediately went to the mound, and manager Terry Francona and team trainers soon followed from the dugout. After a brief conversation, Matsuzaka was removed with what was described as tightness in his right elbow. Given the area of the injury, it appears likely that Matsuzaka will be sidelined for at least precautionary reasons. And so, the Sox are likely to have their first test of rotation depth this year, with Tim Wakefield on the big league roster as a potential fill-in and Alfredo Aceves and Felix Doubront looming in Pawtucket while the team makes a determination about how long they will be without a pitcher who had looked so promising in recent weeks.

Matsuzaka has been on the DL in each of the last three seasons with an assortment of injuries.

While Matsuzaka’s departure had the most lasting implications, it was the bullpen that coughed up Friday’s game. Reliever Matt Albers allowed Ichiro to score when he could not catch the relay on a potential 3-6-1 double play, and Bobby Jenks — summoned in the seventh — continued his recent struggles by allowing two runs on three hits, turning a 4-3 Sox lead into a 5-4 loss.

WHAT WENT WRONG FOR THE RED SOX

–Matsuzaka’s injury, of course, was the most significant development of the game for the Sox. Should the right-hander miss time, the Sox would have a couple of obvious fill-ins, with Tim Wakefield being the most straightforward solution. Alfredo Aceves (on the 40-man roster) was the starter for the PawSox on Friday, tossing five innings and allowing three runs (two earned) while allowing two hits, walking three and striking out five. He threw 77 pitches.

–Jenks has been a disappointment for the Sox in recent weeks. He was strong out of the gate, making four straight hitless appearances to start his Sox career. But since then, he has given up multiple hits in four of his past six outings. Over that six-game span, he has allowed eight runs on 12 hits in 4 1/3 innings, a 16.62 ERA over the stretch. On the year, he has an 8.64 ERA.

–Jed Lowrie went 0-for-4, and is now 2-for-13 since having back-to-back off days on Sunday (when he was given a day of rest) and Monday (a scheduled Sox off-day).

WHAT WENT RIGHT FOR THE RED SOX

–Mike Cameron, who had played in just eight games this year entering Friday, delivered the right-handed thump that the Sox hoped would make him a valuable bench contributor this year. He went deep twice against Mariners starter Jason Vargas for the 16th multi-homer game of his career, and the first since 2009. The first was a pop-up down the right-field line that snuck inside the Pesky Pole; the second was a no-doubt blast into the Monster Seats.

–Adrian Gonzalez went 2-for-4 with a pair of singles, marking his third straight multi-hit game and his fourth in his past five contests. Gonzalez has seen his average go from .263 to .314 during the stretch.

–Had Albers not muffed the throw on a double play, his outing would have been immensely praiseworthy. He logged two innings and allowed one hit while striking out one and walking one. His fastball touched 96 mph on the scoreboard.