BOSTON — Billy Wagner is on his way to the Boston Red Sox, leaving the New York Mets for the chance to pitch in a pennant race as a setup man for All-Star closer Jonathan Papelbon.

After a few days of back-and-forth talks about Wagner's future, the depleted Mets traded the left-handed reliever to the Red Sox yesterday for two players to be named.

The AL wild-card leaders had claimed Wagner on waivers, and the teams worked out a deal that persuaded Wagner to waive his no-trade clause. Wagner's main motivation, according to agent Bean Stringfellow, was his "overwhelming desire to pitch in a pennant race."

"He woke up and decided he wanted to join a team in the middle of a pennant race to have a chance to pitch in October and to have a chance to get a ring, which he's never done," Red Sox general manager Theo Epstein said. "There were some ups and downs and turns in the decision, but in the end he told us he woke up today and really wanted a chance to win a World Series, and came here for all the right reasons."

Boston agreed not to pick up his $8 million option for next season, Stringfellow said in an e-mail to The Associated Press. The Red Sox can still offer salary arbitration to Wagner in the offseason, Stringfellow said, meaning they would be entitled to draft picks as compensation if he signs elsewhere.

The 38-year-old Wagner will join the team in Boston tomorrow.

SHORTS

Santana, Putz can't play: New York starter Johan Santana needs surgery for bone chips in his left elbow and is out for the season. The team said their 30-year-old ace is expected to be ready for spring training next year.

The team also said reliever J.J. Putz will also miss the rest of the season after an MRI revealed "some new fraying and a slight tear" in his right forearm.

Boone to rejoin Astros: Aaron Boone is set to rejoin Houston Friday, about five months after undergoing open-heart surgery, and will be activated when rosters expand on Sept. 1. Boone has been playing in the minor leagues since Aug. 10.

Rays' Crawford hurting: Tampa Bay outfielder Carl Crawford was held out of the lineup against Toronto last night with muscle tightness in his lower back and is likely to miss the final game of the three-game series today. Crawford is batting .316 with 12 homers and 59 RBIs.

Giants' Sanchez on DL: San Francisco second baseman Freddy Sanchez has been placed on the 15-day disabled list because of a strained left shoulder. Sanchez's DL stint is retroactive to Aug. 18, making him eligible to return Sept. 2.

Crede misses 4th game: Minnesota third baseman Joe Crede missed last night's game against Baltimore with a sore back that has now kept him out for four straight games. He was scheduled to have an MRI yesterday, but the results were not immediately available.