NEW YORK — The Yankees remained optimistic and tight-lipped about Gerrit Cole’s prognosis after he left Tuesday night’s game with a tight left hamstring.

“He’s doing pretty well today,” Yankees manager Aaron Boone said. “He went through some testing and that went well. I know he was getting ready to jump on the treadmill right now. So I think he’s encouraged. I don’t think we have anything definitive yet. I think that the next 24 or 48 hours is going to determine where we move and how he responds.

“I think he was encouraged by how he felt coming in here and the start of going through some just different treatment things and what he’s able to kind of [handle] workload wise.”

Cole has not been sent for an MRI on his leg and Boone said they were still monitoring whether he would need one.

Cole said he felt his hamstring tighten up on him after landing funny on a pitch in the fourth inning of the Yankees’ 5-1 loss to the Blue Jays. He signaled for the trainer after giving up a sacrifice fly, realizing he was in a jam and afraid of doing further damage trying to work out of it.

Cole’s next scheduled start would be Sunday night at Citi Field in a nationally broadcast game against the Mets. The Yankees are also expecting the return of Michael King from his rehab assignment and that would also be his night to pitch on regular rest if they need to push Cole back.