"I'm hearing [Lackey] feels good, but we haven't decided anything yet," Maddon said on Tuesday.
Lackey did not undergo an MRI on his shoulder. He felt part of the problem was throwing two bullpen sessions last Thursday. One was a regularly scheduled session between starts, but he also warmed up during the Cubs' extra-inning game against the Cardinals.
"Based on the day off, the doubleheader, the pitchers available, there's things we can do to extend it," Maddon said.
Trevor Cahill was activated from the disabled list to start the first game of the doubleheader against the Brewers, and Maddon was not sure what the right-hander's role would be after Tuesday's outing.
• Maddon said he's not heard anything from Cubs president of baseball operations Theo Epstein or general manager Jed Hoyer regarding Jonathan Papelbon, who was released by the Nationals on Friday. The Cubs have added several relievers over the past few weeks, including closer Aroldis Chapman.
"The [front office has] not discussed him with me," Maddon said. "I have not heard a whole lot of scuttlebutt in the clubhouse, either. I like our group right now. I'm not saying it can't happen, but for right now, there is nothing happening. As long as these guys are well, I have a lot of faith in our group right now."
Epstein and Hoyer know Papelbon well from their time together in Boston. This season, the right-hander had 19 saves in 22 opportunities and a 4.37 ERA for the Nationals. If he joined the Cubs, he would have to accept a role as setup man. Maddon feels the Cubs' clubhouse is strong enough to handle any personality.
"I have a lot of faith in our players that regardless of who we put in that room, these guys would have the new person understand how we do things here, or more important, that's not how we do things," Maddon said. "I do have a lot of faith in our guys."
• Maddon complimented catcher Miguel Montero for being a good mentor to rookie Willson Contreras and dealing with not getting as much playing time as he has in the past.
"The fact that Willson has done so well has put us in a good bind," Maddon said. "I give Miggy absolute credit. He's been fabulous internally with me and everybody else. He's not playing as much as he thought he would now, because this kid has come up. I cannot give him enough credit."
"It's obviously hard to go out there and play maybe once every five days," Montero said. "It's something I don't think about. Whenever I play, I try to have fun. If I start putting pressure on myself -- I need to get a hit, I need to get three hits to make the lineup the next day -- it's a lot more stress. I just go out there and have fun."
• Pedro Strop, who had arthroscopic surgery on his left knee Friday to repair a torn meniscus, was walking without crutches on Tuesday. He is expected to be sidelined for four to six weeks.
• How are the Cubs able to put aside losses so quickly?
"One of my main objectives with any team I'm with is you win hard for 30 minutes and you lose hard for 30, and you move on," Maddon said. "I don't see anything productive about carrying a loss to the next day. There's nothing positive or good that comes from that."