Francisco is on the 15-day disabled list with a left oblique strain. Collins said Francisco's oblique "just didn't feel right."
"He's so big and strong, if he's not ready to go out there, he can do some serious, serious damage to it," Collins said.
Left fielder Jason Bay, however, is progressing toward a return from the seven-day DL. Bay played in a rehab game Thursday in high Class A Port St. Lucie, and Collins said he will play a rehab game in Triple-A Buffalo soon. Collins plans to check with Bay this weekend about his progress.
"I told him when he left, I'm going to call him this weekend, and be honest with how he's swinging," Collins said. "When he feels like he's swinging as well as he can swing, he's coming back."