Boston Red Sox pitcher Daisuke Matsuzaka is returning to Boston to have his ailing shoulder examined, leaving his next scheduled start, Monday in Baltimore, in doubt.

"We are going to send him back to Boston for a precautionary MRI," Red Sox manager Terry Francona said yesterday after emerging from behind a clubhouse office door that was closed for more than an hour while he met with Matsuzaka, the team's training staff and interpreters.

Matsuzaka left his start Tuesday at Seattle before the fifth inning. In four innings, Matsuzaka allowed three runs on four hits. He did not allow a walk and struck out two.

He left the game after throwing two warmup pitches before the bottom of the fifth, briefly holding his back.

"Even before I went on the mound, I felt things were a little bit off in the bullpen," Matsuzaka said late Tuesday. "I wasn't at my best. After pitching the fourth inning, I definitely felt there was something wrong, and I had a conversation with the coaching staff."

Matsuzaka said he had a similar injury during 2000 or 2001, his second and third seasons with Seibu in Japan's Pacific League. But he pitched through that and successfully deep into a game, he recalled. Nothing came of the injury after that.

Boston has been without starter and six-time All-Star Curt Schilling since early March because of weakness in his pitching shoulder. Josh Beckett missed the first six games of the season with a lower-back strain.

Noteworthy

* Commissioner Bud Selig finally got around to announcing what the rest of baseball has known for more than a year: The Angels will host the 2010 All-Star Game. The game will be at Anaheim for the first time since 1989, when Bo Jackson hit a 448-foot homer and was selected MVP. Nolan Ryan was the winning pitcher in the AL's 5-3 victory, and John Smoltz, the only player still active from that game, took the loss.

In games yesterday:

* At Anaheim, Marcus Thames hit two two-run home runs to lead the Detroit Tigers over the Angels, 6-2. Armando Galarraga (4-2) allowed four hits in 8 1/3 innings for the Tigers, striking out four.

* At Oakland, Shannon Stewart drove in Toronto's first run in the third and scored the game-winner in the ninth as the Blue Jays defeated the Athletics, 2-1.

* At Baltimore, Jason Giambi went 2-for-3, hitting a solo homer and an RBI single, as the New York Yankees defeated the Orioles, 4-2.

Melvin Mora drove in the Orioles' two runs with a two-run homer in the third.

* At St. Petersburg, Fla., Matt Garza (4-1) pitched a career-high eight innings, leading the Tampa Bay Rays over the Texas Rangers, 5-3.

Garza allowed two runs and four hits for the American League East leaders, who won two of three from the Rangers to hand Texas its first series loss in more than a month. The Rays have won nine of their last 11 series, including six straight at home.

* At Cleveland, Carlos Quentin drove in three runs, including a go-ahead, two-run double in a three-run seventh inning that led the Chicago White Sox over the Indians, 6-5.

Indians designated hitter Travis Hafner was out of the starting lineup for third straight game because of an injured right shoulder but was optimistic he could avoid a trip to the disabled list.

* At Seattle, Erik Bedard allowed only two hits in seven innings, and Yuniesky Betancourt's home run was all the Mariners needed to beat the Boston Red Sox, 1-0. J.J. Putz earned his sixth save in nine chances, completing the first shutout of the season for Seattle.

* At Kansas City, Justin Morneau hit a leadoff homer in the 10th inning and the Minnesota Twins, after rallying for five runs in the ninth, beat the Royals, 9-8, KC's 10th straight loss. *