There was a reason, it turns out. Posada said he tweaked his left hamstring while stretching on Sunday at Boston's Fenway Park, which led manager Joe Girardi to keep him out of the starting lineup for a second successive game on Tuesday at Comerica Park.
"It's bothering him a little bit," Girardi said. "He said today it's a little better, and we need to get him completely healthy."
Girardi said that he is not afraid to play Posada, as evidenced by his ninth-inning pinch-hit appearance on Monday, but the skipper does not necessarily want him to catch nine innings at this stage. Jose Molina started at catcher for New York on Tuesday, receiving Phil Hughes in his first start of the year.
Posada said that he ran carefully to first base in his at-bat on Monday, which brought in the Yankees' second run of a 4-2 loss to Justin Verlander and the Tigers.
"I was concerned and didn't want to pull it," Posada said. "I could play [Tuesday], but there's no concern about [Wednesday]. The main thing is just running."
Aside from the hamstring, Posada said that he is feeling healthy, as the 37-year-old backstop comes off major right shoulder surgery. Posada's throwing has grown stronger as the season progresses, and he said that there has been no hint of a setback.
"I just hope it doesn't, to tell you the truth," Posada said. "I'm still doing my work with the trainers on the side and things that I've done before. I feel good, and I hope it keeps getting stronger instead of going the other way."
Bryan Hoch is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.