Bay has been on the seven-day disabled list since suffering a concussion June 15 and has been targeting a return for Tuesday's game against the Nationals.
"I'm going to call him after the game, just to see how he feels and have him tell me what's going on," manager Terry Collins said.
Even if Bay is ready to return Tuesday, Collins said he would likely play in Buffalo's game Monday to get some more at-bats.
"He needs at-bats," Collins said. "This is about at-bats. I'm not worried about the fatigue factor. He's been out three weeks resting. I'm not worried about fatigue."