The 24-year-old Zambrano is only 4-3 despite a 3.56 ERA in 14 starts for Chicago this season. The hard-throwing hurler saw his ERA jump up from 2.94 to 3.56 over his last two starts after allowing 10 runs in 11 1-3 innings against the Boston Red Sox and New York Yankees.
Zambrano was roughed up for six runs and nine hits in 6 1-3 innings of Chicago’s 9-6 loss to the Yankees on Friday. He will try to better that effort against the Brewers on Wednesday.
Williams made his first start since being acquired from San Francisco with pitcher David Aardsma for reliever LaTroy Hawkins and cash on May 28. The Cubs hope Williams can fill in at least until injured right-handers Mark Prior and Kerry Wood return from the disabled list, possibly before the All-Star break.
Shortstop Bill Hall was the only Brewers batter to get to Williams. Hall hit a solo homer in the second. In the fourth, he hit the first pitch, another solo drive to left, for his first career multihomer game and a career-high 10 homers this season.
Rookie Prince Fielder played first base for the first time in his big league career. He pinch-hit in Monday night’s loss to the Cubs and was a designated hitter in four interleague games earlier this month.
Fielder, who batted third, went 0-for-4 with a two strikeouts. The 260-pound first baseman was the Brewers first pick and seventh overall in the 2002 baseball amateur draft. He’s batting .238 (5-for-22) with three doubles since making his major league debut on June 13.