"You can't be selfish," said Villanueva, one of five pitchers vying for the final three spots in the starting rotation. "You have to see it from the team's point of view. All I can do is make the decision difficult."
Villanueva had just one rough spot Monday, when he allowed four runs in the third inning of his five-inning stint on the mound. He struck out five and walked none as a Brewers split squad played the Chicago White Sox to a 4-4 tie in 10 innings.
Chicago starter Javier Vazquez was going strong until the fifth inning, when the Brewers tied the game on a three-run homer by Mike Cameron. All three runs were unearned because of an error by third baseman Josh Fields.
Gabe Gross, who homered off Vazquez in the first inning, followed Cameron's blast with a single, prompting Chicago manager Ozzie Guillen to make a pitching change.
"I wanted to face one more batter," Vazquez said. "For me, endurance is the main thing. I seem to have a pretty good feel for all my pitches now. It's all about endurance now."
Guillen didn't agree.
"We don't need any heroes right now," the manager said.
Neither team scored after Cameron's home run.
The White Sox had only one hit after the fifth inning.
Shortstop Alcides Escobar led the Brewers with three hits.
A new wrinkle entered the Brewers pitching derby when left-hander Chris Capuano departed the team's other split-squad game against Seattle in the fourth inning with elbow soreness.
Capuano was examined by a doctor and said he'd be shut down for a few days to see if the elbow calms down.
"The timing is not good in terms of the competition but what concerns me now is my elbow," Capuano said.
The Brewers had to call several players over from their minor-league camp for the split-squad games because left fielder Ryan Braun (tight Achilles' tendon), second baseman Rickie Weeks (sprained right hand) and shortstop J.J. Hardy (flu) all were unavailable to play.