Back puts Colon on the DL

Masterson will stay in rotation

PHILADELPHIA - Red Sox rookie Justin Masterson can take the mound this afternoon with full confidence that his return ticket to Pawtucket has been canceled for the foreseeable future.

Bartolo Colon, who on Monday night took swings at bat that were reminiscent of his former Angels teammate, Vladimir Guerrero, and hurt himself in the process, is going on the 15-day disabled list with what the club is calling a lower back strain. Righthander Chris Smith was recalled from Triple A Pawtucket to take Colon's roster spot. Smith, 27, is 1-2 with a 1.52 ERA and 8 saves with the PawSox.

Sox starters had gone at least five innings in 17 straight games until Colon bowed out after four innings of the 8-2 loss to the Phillies. By then, he'd allowed three home runs - two to Ryan Howard - and was hurt swinging so violently at a Cole Hamels changeup that his helmet tumbled off.

The injury didn't appear serious; unlike Kevin Youkilis, who experienced back spasms during batting practice and wore an ice wrap around his torso, Colon did not appear the worse for wear after the game. He said he expected to make his next start.

That decision was taken out of his hands by the Sox, who are prepared to activate Daisuke Matsuzaka from the DL Saturday, when Colon had been scheduled to make his next start.

Colon has been a boon for the Sox; in six starts, he is 4-2 with a 4.09 ERA and, just as important, allowed the club to send Clay Buchholz to Pawtucket for some polishing. But with his history of arm problems - he had a torn rotator cuff in 2006, an elbow impingement last season - the Sox embraced the idea of giving him some time now in hopes that he'll still be productive in late summer.

"He's got a history of issues," manager Terry Francona said. "That's why we're somewhat cautious with him. We'd like to have him the whole year, healthy and productive."

Francona said he and pitching coach John Farrell were not comfortable with Colon's arm slot after his fourth-inning at-bat, which is why they lifted him even after he retired the side in order in the bottom of the fourth.

Masterson made the decision easier. He comes into this afternoon's game with a 3-1 record and 2.90 ERA in five starts. Matsuzaka breezing through his rehab start Monday night for Pawtucket (5 IP, 3 H, 2 ER, 1 BB, 5 K, 65 pitches) cinched it.

Rest for Beckett

With a day off tomorrow, the Sox will tweak the rotation to give Josh Beckett a couple of extra days off. Tim Wakefield, Matsuzaka, and Jon Lester will pitch with regular rest this weekend against the Cardinals; Beckett, who pitched last Sunday, will work the opener Monday against the Arizona Diamondbacks. "We talk about building in rest," Francona said. "Josh knew all along. He's fine." . . . Curt Schilling was returning ahead of the team to see Sox medical director Thomas Gill to discuss where he goes next in his efforts to rehabilitate his ailing right shoulder. His last throwing session, Friday in Cincinnati, did not go well - Francona called it a "plateau" - and it appears Schilling's intention of facing live hitters will have to be pushed back indefinitely . . . Youkilis was out of the lineup last night for the second straight game with back spasms, and Francona hinted he may not play today, with the off day potentially giving him a fourth day to recover . . . Assistant general manager Jed Hoyer played ballpark tour guide for Sox draft choice Derrik Gibson, a shortstop from nearby Seaford High in Delaware who was the team's third pick, taken at the end of the second round.

Favorite target

Manny Ramírez vs. Jamie Moyer matched the slugger with the pitcher he has taken deep more than any other. Ramírez has 10 home runs off Moyer, though he managed just a single in three trips last night. The only pitcher who has given up as many home runs to a player still active is Greg Maddux, who has surrendered 10 to Luis Gonzalez . . . The Single A Lowell Spinners opened their season last night at LeLacheur Park. Gary DiSarcina is back to manage. The Sox announced they have extended their player development contract with the Spinners through 2010 . . . J.D. Drew leads the majors with eight home runs in June. Jackie Jensen set the club record for the month with 14 in 1958.