For a while, Jason Shiell thought his promotion was a prank.

After the Boston bullpen's latest collapse Tuesday night against Tampa Bay, the Red Sox purchased Shiell's contract from Class AAA Pawtucket and optioned RHP Bob Howry to Pawtucket.

Shiell, 26, was out to dinner with his teammates in Ottawa, where the PawSox were playing. When he got the call, he thought one of his teammates was pulling his leg.

"I was pretty surprised," he said. "I was at a steak house . . . someone got on the intercom and said you have to call [Pawtucket Manager] Buddy Bailey. I thought they might have been kidding."

Howry gave up 11 hits and six runs in four games for a 12.46 ERA. Ramiro Mendoza has a 16.71 ERA after seven appearances.

"This is a move that we had contemplated for several days," Red Sox GM Theo Epstein said. "It's not a message. It's just a move to get a guy going."

* SURGERY FOR NEN: Giants closer Robb Nen, who has been on the disabled list since Opening Day, will undergo arthroscopic surgery on his ailing right shoulder Friday. He is the team's career leader in saves with 206. He has 314 saves in his 11-year career.

-- From News Services