"He had it [Monday]," Collins said of the discomfort. "It's not much better today. I just said, 'Look, the one thing I don't want you to do is go out there and do something that's going to cost you the remaining seven games of the season.' So we'll give him the day off."
That line of thinking is nothing new for Bay, who missed significant time earlier this year with a fractured rib and a concussion. Multiple concussions, bone injuries and muscle strains have undermined Bay's three years in New York, landing him on the disabled list at least once per summer and causing him to miss more than 150 games -- roughly one full season.
It is impossible to quantify how much that has played a role in Bay's lack of production when healthy, but it certainly cannot be discounted. When healthy enough to play this season, Bay has hit just .155 with eight home runs, down even from his career-low stat lines in 2010 and '11.
"I think it might be two separate things," Collins said of Bay's injury history and lack of production. "Jason Bay is one of those guys who does play less than 100 percent. He's just a gamer. He just goes out and plays. It's tough for me to answer how that reflects on the fact that he hasn't produced here. I don't know how bad he's been hurt in the past."
Regardless, general manager Sandy Alderson said recently that the team has no intention of cutting Bay this offseason and eating the guaranteed $19 million remaining on his contract.