Heisey is nursing a mild left groin strain after he said he felt tightness when he crossed the plate in the fourth inning of Cincinnati's win against the Indians on Thursday. Stubbs' recovery from an oblique injury has been slowed by a flu-like virus making its way through the Reds' clubhouse.
"Right now, we're kind of mixing and matching," Baker said. "It really hurts when you've got both center fielders down. Most teams are lucky to have two. We have a real good one in Stubbs, and Heisey plays a real good center field."
As a result, Wilson Valdez made his third career appearance in center field Friday in New York, and his first career start there. Rookie Kristopher Negron filled in Thursday.
"For me, it's all the same," Valdez said. "You have to go out there with the mindset of doing whatever you have to do to help the team win."
The Reds transferred right-hander Nick Masset to the 60-day disabled list (sprained right shoulder) Friday and officially placed Stubbs on the 15-day DL retroactive to June 6 with hopes of him returning when the club heads back to Cincinnati next weekend.
The team selected utility man Willie Harris from Triple-A Louisville to fill the empty roster spot. Harris, the only non-roster player to make the Reds' Opening Day roster, was outrighted to Louisville on May 7 and has played second base, third base, shortstop and outfield there.
Baker said Heisey, who is batting .275 with a homer and 12 RBIs in 53 games this year, should not be sidelined for long.
"Heisey's a little tight," Baker said. "He didn't pull it. It's just tight. That's a plus. With the big ol' strong legs he has, tight means real tight."
Baker also said that catcher Devin Mesoraco, who also left Thursday's game with muscle cramps in his side, appears to be OK.