PHOENIX (AP) -- Carlos Zambrano wants to start on opening day for the Chicago Cubs, and he's not shy about it.

"I care," Zambrano said Saturday during a 2-0 loss to the Milwaukee Brewers. "When you're retired and you go home and your grand kids ask you what you did, for your own records it's good."

Cubs manager Lou Piniella said earlier in the day that the April 6 assignment against Houston will go to Zambrano or Ryan Dempster.

Zambrano was 14-6 with a 3.91 ERA last year, while Dempster finished 17-6 with a 2.96 ERA. Piniella said he would talk to both pitchers before making his decision.

"My answer would be me," Zambrano said. "And I guarantee you that (Dempster's) answer would be him."

In other news, reliever Eric Gagne, who came to Brewers camp looking for a roster spot, is likely finished in Milwaukee after a second doctor reported the right-hander has a frayed rotator cuff.

Gagne was 4-3 with 10 saves and a 5.44 ERA for the Brewers last season.

Zambrano was given the option of pitching in a simulated game Saturday at the Cubs' complex in nearby Mesa, but he chose to face the division-rival Brewers.

Milwaukee fielded what likely will be its starting lineup minus left fielder Ryan Braun, who is participating in the World Baseball Classic.

"I said I wanted to face them so I could start to feel like it's close to the regular season," Zambrano said. "It's good to face good hitters. It makes you go with more intensity."

Zambrano allowed two runs and three hits over four innings with five strikeouts. Both runs came when he overthrew first base on Mike Lamb's comebacker to the mound.

"I think I made a rookie mistake," Zambrano said. "I should have taken it nice and easy and not rushed. Obviously, I was too rushed and it happened."

Brewers starter Jeff Suppan was sharper, scattering three hits over three scoreless innings.

"He got his work in and moved the ball around," manager Ken Macha said. "He got some outs with his fastball and that was good to see."

Suppan and four relievers, including possible setup man Carlos Villanueva, held the Cubs scoreless on seven hits with only one walk.

Macha said he was most pleased by Villanueva, who struggled with high pitch counts in previous outings.

"He's been somewhat of a concern but he had a couple of good innings today," Macha said.

Third baseman Aramis Ramirez and left fielder Alfonso Soriano returned to the Cubs' lineup. Soriano led off the game with a single to right and went 1-for-4. Ramirez finished 1-for-3.

Notes: Cubs OF Milton Bradley took Saturday off as part of his every-other-day schedule. ... Brewers RHP Braden Looper continued his recovery from a strained ribcage muscle with a session of long toss. ... Brewers RHP David Riske, recovering from elbow surgery, will throw 20 pitches in a simulated game Sunday.

(Copyright 2009 by The Associated Press. All Rights Reserved.)