"It felt better," Lilly said Friday after playing catch. "It wasn't something I was real concerned about. ... I want to do everything I can to be healthy and have the best season possible."
Lilly had arthroscopic surgery on his left knee last July, but said the soreness he felt in recent days wasn't as bad as last year.
"The MRI showed he had a little wear and tear on his knee, but he was able to do his work, get his throwing in and he had no discomfort at all," Cubs manager Lou Piniella said. "We're going to modify his training program, probably a little less running, a little more bike, those sort of things. We're just going to monitor it and see how he is. It's good news for us. It could've been a lot worse."
Lilly does like to run but understands he needs to switch up his cardio workouts.
"The idea is to stay off it," the left-hander said of his knee. "That's the advice I've been given. It makes sense but it's not as much fun. You do whatever you can do and whatever adjustments need to be made."
Lilly is rehabbing from arthroscopic surgery on his left shoulder, which he had in early November. He could be ready as early as mid-April.
Carrie Muskat is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.