Lieber, who spent the previous three seasons in Philadelphia and underwent surgery for a ruptured tendon in his foot last year, will compete for a spot in Chicago's rotation when the Cubs report to spring training next month. He can earn performance bonuses based on games started and innings pitched.
"He gives us some depth. There is no sense playing mix and match and who's going to be this and what role somebody is going to have," general manager Jim Hendry said. "We're just trying to add as many quality pitchers and we think he adds a lot still to our club."
The 37-year-old Lieber was disappointed when the Phillies initially assigned him to the bullpen at the start of last season. But he said Wednesday he'll be willing to accept any role in his return to the Cubs.
"I'll do whatever it takes to help the Chicago Cubs win and if that's pitching out of the bullpen, so be it," he said.
Lieber had elbow ligament replacement surgery in 2002 -- the final year of his first stint with the Cubs -- and was bothered by a groin problem with the Phillies in 2006. Last year, his season ended on June 20 because of the foot injury.
Now, he says he's healthy and ready to pitch. He said he completed his lengthy rehab in early October.
"Everything is fine and I've been cleared to do my normal routine since then and had no problems," Lieber said.
"We're going to have probably seven or eight starters in camp and that's the right number," manager Lou Piniella said Wednesday during a stop on the team's winter tour. "Lieber competes very well, knows how to pitch. Let's hope he's nice and healthy and ready to go. If he is, he will help us."
Hendry said the Cubs will be busy during the weeks leading up to the start of spring training on Feb. 13 in Mesa, Ariz. Chicago won the NL Central last season before getting swept by Arizona in the first round of the playoffs.
"I don't get into other teams' players," Hendry said. "We're going to try to be really aggressive the next three or four weeks before camp and try to come up with somebody else who can help us before we get there. ... We're going to try to stay on top of it."
The Cubs have already added Japanese star Kosuke Fukudome to be their right fielder, and reports said they were also interested in second baseman Kaz Matsui, who signed with Houston.
Mark DeRosa, who displayed his versatility by playing several positions last season but was primarily a second baseman, is back.
Piniella was perfectly happy with DeRosa's performance, which included a .293 batting average with 10 homers and 72 RBIs in 149 games.
"I know when we signed him we talked about moving him around a little bit, but let me tell you, if we went to camp just the way we are with Mark at second base, it's fine with me," Piniella said.
Lieber is 129-121 with a 4.28 ERA in 375 major-league appearances, including 326 starts. He was 48-36 with the Cubs from 1999-2002, including 20-6 with a 3.80 ERA in 2001 when he made the NL All-Star team. He has also been especially effective at Wrigley Field, with a 29-18 record.
Lieber also pitched for the Pittsburgh Pirates and New York Yankees. After missing the 2003 season while recovering from elbow surgery, he went 14-8 with a 4.33 ERA in 2004 with the Yankees. He was 17-13 with a 4.20 ERA in 2005, his first season with Philadelphia.