MILWAUKEE -- The Brewers sent pitcher Brandon Sproat back to Triple-A Nashville after he allowed four runs in the ninth inning of an 8-6 victory over the Cubs on Wednesday.

Sproat pitched a scoreless eighth, then walked four of five batters in the ninth with a throwing error and wild pitch. "It's unacceptable," manager Pat Murphy said. "You've got to throw the ball over the plate or you can't be a major league pitcher."

Sproat left with the bases loaded and one out in an 8-2 game. Abner Uribe got the final two outs after the Cubs scored four runs. The Brewers called Sproat up Monday to try a bullpen role; Wednesday was his first appearance. He had spent much of the season in Milwaukee's rotation before being sent down in early August. He is 3-7 with a 5.57 ERA in 22 appearances, including 19 starts.

The Brewers acquired Sproat and infield prospect Jett Williams before the season in a trade that sent two-time All-Star pitcher Freddy Peralta to the New York Mets. The Mets sent Peralta to the Tampa Bay Rays at the trade deadline.