Collins said Francisco, who is on the disabled list, will be seen by a doctor this week.
"They thought he was making progress, ready to go to Binghamton, and he didn't feel very good so we thought he should see the doctor again. That's what we're going to do," Collins said Sunday before the Mets faced the Pirates. "Now, what the leads to, I have no idea, but we did not have any date etched in stone that we knew he was coming. It's one of those things when you have a guy on the disabled list, you wait until he tells you he's ready to pitch."
Francisco, who has elbow inflammation, seemed close to a return before experiencing the discomfort, as he was headed to Double-A Binghamton to pitch this weekend. Francisco's 30-day rehab window is set to expire Thursday, and he already had pitched five scoreless innings for the Class A St. Lucie Mets. Francisco last pitched May 8 and had even pitched on back-to-back days.
The reliever had offseason surgery in December to remove a bone spur from his right elbow, and inflammation flared up during spring training. He also experienced the inflammation last season.
Francisco is in the second season of his two-year, $12-million deal with the Mets. He recorded 23 saves but had a 5.53 ERA last year. Bobby Parnell has been the team's closer in his absence.
While there had been talk about Francisco being activated to replace Jeurys Familia (biceps tendinitis), who was placed on the DL Sunday retroactive to May 9, the team instead had to recall reliever Greg Burke. Familia hasn't pitched since May 8, and while Collins said the team possibly could have kept him a few more days, a depleted bullpen made the move necessary.
Collins said Familia told him he's feeling better Sunday, and the reliever has been shut down.
"He said he still has some symptoms of tendinitis. I just told him he has to slow down. He'll go down to Florida with the rehab guys and take a few more days and let it rest and get all the treatments, do all the strengthening exercises and then start throwing," Collins said. "He's throwing very well. We can backdate it. I'm hoping in those 11 days he'll be ready to come back."
Burke signed with the Mets in the offseason and pitched to a 7.36 ERA in seven games before being sent down to Triple-A Las Vegas on April 18.
"It was a good time that I had down there as far as working mechanically and figuring out what I needed to do. Just be more consistent, pretty much," Burke said. "It sounds like we could use some innings here so it's always good to help."