FORT MYERS, Fla. — Red Sox manager Terry Francona said that shortstop Julio Lugo underwent a successful arthroscopy on his right knee this morning to repair his torn meniscus. He will remain in Boston for the next five to seven days. The shortstop is expected to be sidelined for three to four weeks. With Opening Day just under three weeks away, math is working against Lugo’s ability to play when the curtain lifts on the regular season on April 6.

“It looks like he’s certainly not going to be ready to start the season,” said Francona. “That’s stating the obvious.”

That leaves the door open to the group of Nick Green, Angel Chavez, Ivan Ochoa and Gil Velazquez in the competition to serve as a backup middle infielder behind Dustin Pedroia and Jed Lowrie, who will now serve as the season-opening double-play combination.

Some other notes from Francona’s morning session:

–A total of six players had to make the trip to the other side of Edison Ave. Catcher Mark Wagner was optioned to Double-A Portland, left-hander Hunter Jones was optioned to Triple-A Pawtucket and left-hander Felix Doubront was optioned to High-A Salem. Outfielders Josh Reddick and Zack Daeges as well as first baseman Lars Anderson were all re-assigned to minor-league camp.

Francona said that the entire group had been impressive in its time in big-league camp. Anderson, however, suggested that he wasn’t locked in at the plate (he batted .182), and at some point in the conversation with the manager, used the word “disappointed” to describe how he felt about his performance. Francona had a simple reassurance to offer: “We look at you and see what you’re going to do,” Francona told Anderson. “It’s exciting.”

–Dustin Pedroia took soft toss, but won’t be allowed to take batting practice until Thursday. (He will take live batting practice at that time.) He will take some grounders today (indeed, he is taking the pivot at second base as I write).

–Brad Penny is slated to throw two innings at the minor-league complex on Wednesday. If all goes well, that would put him in line to make his first Grapefruit League start the following week. Tim Wakefield will throw four innings at the minor-league complex on Thursday, when he’ll be paired with catcher Josh Bard.

–Minor-league games between the Red Sox and other organizations will begin on Wednesday. To this point, there have only been intrasquad games.