It will be Lilly's first start of the season after he rehabbed from last November's arthroscopic surgery on his left shoulder. Manager Lou Piniella said Lilly should be fine to throw 75-80 pitches in his 2010 debut.
Lilly tuned up with a rehab start Monday for Class A Peoria.
"Obviously, we're going to get some questions answered," he said. "I feel good. I don't have any reservations as to why I should be going out there. I'm healthy, and I'm ready to contribute."
Lilly was 12-10 last year with a 3.10 ERA. Knee and shoulder problems limited him to 27 starts and 177 innings.
The Cubs will have to make a roster move Saturday when Lilly comes off the DL. They'll send a relief pitcher down from a group that includes left-hander James Russell and right-handers Justin Berg and Jeff Samardzija.
Piniella said the decision will be based in part on how many lefties the Cubs want in the pen. Already, they have Russell, John Grabow and Sean Marshall. Russell has pitched no worse than anybody else in a shaky bullpen, but he may be squeezed out in a numbers game.
--Aramis Ramirez did not start for a second straight game as he works with hitting coach Rudy Jaramillo on his swing. Ramirez, who is batting .127, did not start Thursday at New York but got into the game late.
"(Thursday), I was going to give him the day off, but we were trying to win a baseball game, and I had to use him," Piniella said before the game. "He'll get some more work (Friday), and we'll get him in there (Saturday). We need for Ramirez to hit."
Chad Tracy started at third base in place of Ramirez Friday.
--Carlos Zambrano is set to make his bullpen debut Saturday against the Brewers. Zambrano started this past Tuesday at New York and threw 119 pitches. Piniella wanted Zambrano to watch Friday's game from the bullpen.
--Marlon Byrd is batting .476 (10-for-21) on the current road trip. He said an effort like Friday's takes the pressure off the starting pitching staff, which has pitched well but has been victimized by poor support and a shaky bullpen.
"We're a good team," Byrd said. "We're going to score our runs. It's a work in progress. Guys are working hard, trying to find their swings."
--Dempster has won his last four starts against the Brewers. He's 2-0 overall this year with a 2.60 ERA.
"Maybe facing them so many times," Dempster said. "They've had some success off me, too. I figured they scored 20 (Thursday), they had to hit a few of those at somebody (Friday)."
--Ryan Theriot extended his hitting streak to three games (7-for-15) with a double to start the game and a fourth-inning RBI triple. Theriot has bounced between first and eighth in the lineup lately. He batted leadoff Friday and raised his OBP to .320 and his batting average to .275.