Dating to last season, Jungmann is 0-7 with a 9.35 ERA in his past nine starts.
"I'm hoping he can get on track quickly and come back here," Brewers manager Craig Counsell said. "But we have to get him on track. We just need better."
The Brewers don't have an open date on their schedule until May 16, so they'll need another starting pitcher for Tuesday's game at Miller Park against the Angels. They have already promoted one starter -- Zach Davies -- to replace injured veteran Matt Garza, who resumed throwing on Friday but remains more than a month away from returning from a lat strain.
Top pitching prospect Jorge Lopez is on the 40-man roster and happens to be on a schedule that coincides with Jungmann's, but Lopez has an 8.79 ERA after four Triple-A starts. Counsell indicated the club doesn't plan to move a reliever to the rotation, disqualifying left-hander Chris Capuano.
By rule, Jungmann must remain in the Minors for at least 10 days.
"I would say 'searching' is an accurate word," Jungmann said in Chicago. "On the mound, when I'm struggling, I tend to search rather than just compete, and I think I still haven't got past that. …
"I think right now I'm a little timid for whatever reason. That's never been me, but I think it's obvious when you watch the game. Too much going on in my head and not competing."
Jungmann will try to clear his mind in Colorado Springs, where he was 2-3 with a 6.37 ERA in nine starts plus two relief appearances last season before a promotion to Milwaukee in June. The SkySox's home park sits at a higher elevation than Denver's Coors Field, and is one of professional baseball's most challenging venues for pitchers.
But if he stays on his current schedule, Jungmann's first two starts would come in Colorado Springs.
"We can define this and it doesn't have to be like -- he doesn't have to win three out of four starts or anything like that," Counsell said. "We've got enough eyes on him to feel like we'll know when he's put it together. That's a big trick with Colorado Springs. We have to not only evaluate the line score, but we have to evaluate with the eyes we have there. We'll do that. Your pitching lines there are going to be different."
Garza, meanwhile, made progress Friday. He made 30 throws on flat ground from 60 feet, representing the first step in building back to pitching shape.
"It's going to be real slow, but I'm happy to be throwing again," Garza said.
He is eligible to come off the disabled list June 1.