"It could be a rehab start, maybe if he feels really good we'll do something else with him," he said. "We have options, obviously."
Bannister has been on the disabled list since April 28 with a strained right hamstring. He has been working out in Port St. Lucie, Fla., and threw 83 pitches Saturday.
If Bannister is deemed ready to return to the rotation, he likely would take the spot of Jose Lima. In two starts, Lima (0-2) has given up 10 earned runs in 9 2/3 innings.
"If he comes around well and feels 100 percent and is throwing the ball well, that's a possibility," Randolph said of the chances of Bannister starting Thursday.
Besides Bannister, right-handed starters Victor Zambrano and John Maine are on the disabled list.
Floyd sits: Randolph kept Cliff Floyd out of the starting lineup on Saturday night, and said the outfielder might sit out Sunday's game, too.
The team has an off-day Monday, so Floyd could get three days off to "clear his head," Randolph said.
"I'm thinking about it," he said. "Sometimes it's best to get a nice, little break."
Floyd is batting .197 with three home runs and 14 RBIs.
"He's struggling, obviously, so sometimes it's best to get a little break," Randolph said. "He might be in there [Sunday]."
Floyd said he did not blame Randolph for taking him out of the lineup.
"Clear your head? That stuff, in my opinion, is great to hear when you are struggling," he said. "But the outcome of it all is hits. That's what it boils down to."
No panicking: Despite losing four of five games going into Saturday night's contest at Milwaukee, Carlos Delgado said the veteran leadership on the Mets has helped the team keep an even keel.
"We've got more depth," he said. "We're got so many guys who can carry the load. That makes it all easier.
"It's important that we pick each other up when we go on the field," he said. "We're pulling for each other, trying to make each other better."
Fortunato's season over: The team said right-handed reliever Bartolome Fortunato would undergo season-ending Tommy John surgery on his right elbow next week.
Mets medical director David Altchek will perform the procedure Thursday at New York's Hospital for Special Surgery.
In two games, Fortunato was 1-0 with a 27.00 ERA in three innings.
Fortunato's option to Norfolk earlier this week was voided, and he was placed on the 60-day disabled list. That opened a spot on the 40-man roster for left-hander Jeremi Gonzalez, who made his Mets debut Saturday night.
Reliever Heath Bell was optioned to Norfolk to make room for Gonzalez on the 25-man roster.
Rare start: Jose Valentin took Floyd's spot in the lineup, only his third start of the season.
"I haven't faced a lefty yet," Valentin said before the Mets played the Brewers and their left-handed starter, Dana Eveland. "I'm going to go up there and do my best."
Coming up: Pedro Martinez will face left-hander Doug Davis in the final regular-season game between the teams on Sunday afternoon. Carlos Beltran, Floyd, Xavier Nady, Paul Lo Duca, Delgado and David Wright all use Louisville Slugger bats and will take part in a pink bat promotion to create awareness about breast cancer and the importance of early detection. If Floyd is held out of the lineup for a second consecutive game, it will deprive fans a chance to see "Pink Floyd."