"He's going through a little bit of a dead arm period," Maddon said Friday of Lester. "He more than likely will not miss the start after that, but we wanted to be very cautious with it right now and at this point, it does not impact Opening Day."
Lester, scheduled to open the Cubs season on April 5 against the Cardinals, reported to camp in good shape, and Maddon said the lefty may have done too much to "try to impress everybody."
"I checked with him this morning and he felt great," Maddon said.
Lester told the Cubs staff that he's experienced this before, but Maddon was not sure when.
"A lot of times, when you talk to a pitcher and you ask how they're feeling, when a guy smiles easily and talks easily and is upbeat about it, it's a pretty good indication [everything's good], and he was all of that," Maddon said. "I really feel well or strongly that he's going to be OK."
Carrie Muskat is a reporter for MLB.com. She writes a blog, Muskat Ramblings, and you can follow her on Twitter @CarrieMuskat. This story was not subject to the approval of Major League Baseball or its clubs.