MILWAUKEE -- The Brewers designated left-hander Dallas Keuchel for assignment on Sunday, ending for now the former American League Cy Young Award winner’s bid to re-establish himself as a Major League starter.

Club officials, including general manager Matt Arnold, informed Keuchel of the decision on Saturday after the 36-year-old -- staked to a 5-0 lead in the first inning -- ran into trouble in the fourth on the way to a 6-5 Brewers loss to the Nationals. He had a 5.40 ERA and a 1.86 WHIP in four starts for Milwaukee.

“Obviously, Dallas has a great pedigree and he kept us in a lot of games,” Arnold said. “He did a great job for us. It comes down to the number of players that we have coming back. We have some tough decisions to make.”

Among the injured pitchers far down the rehab road are starters Joe Ross and DL Hall and relievers Devin Williams and Jared Koenig. Williams’ scheduled rehab appearance was rained out Saturday, and he was slated to pitch Sunday instead for High-A Wisconsin -- his first appearance since landing on the IL in Spring Training with stress fractures in his back. Ross (back) and Koenig (left forearm) are scheduled to appear for Triple-A Nashville on Friday.

Hall (left forearm) is still recovering from a comebacker off his pitching arm in his last appearance for Nashville, which was supposed to be his last. Once he’s able to resume pitching again, the Brewers intend to keep him stretched out as a starter or bulk reliever.

“It’s a tough decision for Keuchel, and certainly there’s a chance he could stay with us,” Arnold said. “We spoke to him, and he was great. He’s a real pro. Everything he’s accomplished in his career, we want what’s best for him.”

Keuchel was pitching for Seattle’s Triple-A affiliate when the Brewers acquired him for $1 last month and signed him to a Major League deal worth a prorated portion of $1.5 million. Since then, the club has also acquired right-hander Aaron Civale from the Rays and inserted him into the rotation.

Like Keuchel, Civale tends to pitch to weak contact. But too much contact proved problematic for Keuchel against the Nationals, who strung together five consecutive hits to open the fourth inning on Saturday before the Brewers called for long man Jakob Junis, who managed to extinguish the threat with Milwaukee ahead, 5-3.

Opponents hit .329 against Keuchel in his four Brewers starts.

“I don’t like coming out of the game in the fourth inning,” Keuchel said. “But as I calmed down a little bit, [I realized] that my stuff is playing way better than even last year. It’s just one of those outings when things didn’t go your way.”