LOS ANGELES Angels righthander Jered Weaver will be out for at least a month after the ace broke a bone in his left elbow.

The Angels put Weaver on the 15-day disabled list, and the durable 20-game winner's non-throwing arm was in a blue sling while his teammates took batting practice before their Angel Stadium opener against Oakland.

"This is all new to me," Weaver said. "I've never broken anything before, and didn't really know how to take the news. It kind of was a shock at first, and now you've just got to play the waiting game, I guess."

Weaver left Sunday night's loss to the Texas Rangers early after jamming his non-throwing arm while dodging a line drive back to the mound. The Angels initially thought Weaver had only strained his elbow, but Weaver felt abnormal pain after the game, and an MRI exam on Monday unexpectedly revealed a fracture expected to sideline him 4 to 6 weeks.

Manager Mike Scioscia promoted righthander Garrett Richards from the bullpen to replace Weaver in the rotation, and the Angels called up righthander Dane De La Rosa, who just joined Los Angeles in a trade with Tampa Bay last month.

Weaver had his first 20-win season with a 2.81 ERA last year, throwing a no-hitter against Minnesota along the way.

In other news:

* Tampa Bay righthander Jeff Niemann decided on season-ending shoulder surgery after his arm didn't respond well to a move to the bullpen. Niemann's surgery to repair his labrum and rotator cuff will be performed Wednesday by Texas Rangers team doctor Keith Meister.

* Texas is leaning toward skipping lefthander Matt Harrison in the rotation Thursday as the struggling Opening Day starter continues to deal with a sore back.

* St. Louis closer Jason Motte faces reconstructive elbow surgery if his condition does not improve in the next 3 weeks or so. Motte has been shut down since late March because of a strained elbow.

In interleague games * 

At Washington, Adam LaRoche ended an 0-for-15 start to the season with homers in consecutive at-bats, Jayson Werth and Ian Desmond also homered, and the Nationals edged the Chicago White Sox, 8-7.

In NL games * 

At Miami, Kris Medlen allowed only an unearned run in seven innings, and the Atlanta Braves earned their fifth consecutive victory by beating the punchless Marlins, 3-2. The Braves improved to 7-1, their best start since 2007. The Marlins fell to 1-7. Evan Gattis hit his second home run, and Justin Upton doubled home a run.

* At San Diego, Will Venable homered and hit a bases-loaded triple for the Padres, who rebounded from a dreadful six-game trip to win their home opener, 9-3, against the rival Los Angeles Dodgers.

* At St. Louis, Lance Lynn struck out 10 in six innings and rookie Matt Adams connected for his first career pinch-hit homer as the Cardinals beat Cincinnati, 5-1.

* At Chicago, pinch-hitter Scott Hairston had a go-ahead sacrifice fly in the eighth inning and David DeJesus added a two-run single, lifting the Cubs over Milwaukee, 6-3.

In AL games * 

At Kansas City, Jeremy Guthrie (2-0) won his seventh straight decision and Alcides Escobar had three hits and an RBI as the Royals beat Minnesota, 7-4.

* At Cleveland, Robinson Cano hit one of New York's five homers and drove in five runs, Andy Pettitte (2-0) pitched seven solid innings and the Yankees romped to a 14-1 win over the Indians.

* At Arlington, Texas, Nick Tepesch pitched into the eighth inning in his major league debut, Lance Berkman had a key two-run single and the Texas Rangers beat Tampa Bay, 6-1.

* At Detroit, Miguel Cabrera hit his first homer and drove in four runs, leftfielder Don Kelly made a home run-robbing catch and the Detroit Tigers beat the Toronto, 7-3.