"He's giving me the night off," Wagner said, referring to Mets manager Jerry Manuel.
Wagner tested his left shoulder after he arrived at Shea Stadium Tuesday and experienced no new or residual problems. But after he met with Manuel, Wagner learned he had fulfilled a prophecy he spoke in passing on Sunday.
"I'll miss the first game [of the Phillies series], and if we're winning by more than three, that won't matter," Wagner said on Sunday.
Examination of Wagner's left shoulder on Tuesday morning determined he suffered no structural damage, but rather the tightness he has experienced is the result of spasms in the muscles surrounding the joint.
Wagner's availability for subsequent games against the Phillies -- and for the Mets' ensuing series against the Cardinals and Marlins -- is largely dependent on how he feels when -- and if -- the bullpen telephone rings.
Wagner experienced tightness as he warmed up in the bullpen Sunday in Cincinnati and was visited on the mound by Manuel and trainer and Ray Ramirez during the at-bat of Paul Bako, the inning's first batter.
Wagner then fanned Bako and the next two batters to save the 7-5 victory. He decided during the team's flight home that he felt better.
He was examined Monday in Greenwich, Conn., by a club-affiliated doctor and then underwent an MRI early Tuesday in Manhattan.
Wagner said Sunday he had been bothered of late by discomfort in his left trapezius muscle. The tightness he experienced Sunday was in an adjacent area of his left shoulder. He said the discomfort felt like a cramp or spasms, and he suggested that a nerve might be impinged. His self diagnosis was, "My shoulder's a little tight."
The trapezius has bothered him for about two weeks.
"I'm old," said Wagner, who turns 37 on Friday. "I'm supposed to hurt."
Wagner said he had experienced similar problems in the past and solved them by "going out and pitching." He threw 16 pitches, 10 for strikes, Sunday to earn his 24th save in 30 opportunities. He pitched one inning Thursday night after pitching one in the All-Star Game on Tuesday night.
Marty Noble is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.