There was no hiding the disappointment in general manager Doug Melvin's voice Friday afternoon while discussing the news that the Milwaukee Brewers have lost their young ace, Yovani Gallardo, probably for the season.

"It's pretty devastating, a kick in the stomach," Melvin said by phone from Houston where the Brewers were to open a three-game series against the Astros Friday night.

Gallardo, 22, learned Friday morning in Milwaukee that he had a torn anterior cruciate ligament in his right knee, the result of a collision and a twisted landing on his right leg in the fifth inning of Thursday's 4-3 victory over the Chicago Cubs.

"He's obviously down in the dumps," Melvin said of Gallardo, who was making his third start of the season after recovering from cartilage surgery on his left knee early in spring training. "But it's even more devastating to the guys on the club.

"They saw him (Thursday) get up after it happened and go out and pitch (1 2⁄3) innings, showing how much heart and soul he has. It's a real downer, a real bummer."

The news about Gallardo came just a few hours after the Brewers designated reliever Derrick Turnbow for assignment. The Brewers have 10 days to trade or release Turnbow or get him to accept an assignment in the minor leagues.

The Gallardo-Turnbow situations resulted in two other moves to keep the active roster at 25 players.

Dave Bush, sent to Class AAA Nashville Sunday, was recalled to replace Gallardo. Presumably, Bush will take Gallardo's spot in the rotation.

Utilityman Joe Dillon, sent to Nashville on April 20 when the Brewers added to their pitching staff to provide insurance for a then-injured Ben Sheets, was recalled to take Turnbow's spot on the roster.

The Brewers now are carrying 13 pitchers and 12 position players, the first time manager Ned Yost has had four reserves in the dugout since April 20.

Gallardo returned to Milwaukee after Thursday's game instead of accompanying the team to Houston. "We were close to home and he wasn't going to pitch in Houston, so we figured we'd have the knee looked at," Melvin said.

The Brewers are holding back on a decision about surgery for Gallardo until the swelling reduces in the knee.

"I guess you always have to plan for the worst," Melvin said.

Gallardo had not picked up a decision in his three starts but allowed just five earned runs in 20 innings, a 1.80 ERA. Two of those runs came in the sixth inning Thursday against the Cubs, the inning after he injured his knee.

The Turnbow decision did not come as a surprise. It was reported there were hints Thursday morning before the game at Wrigley Field that the team was considering some sort of move for the reliever who allowed six runs, six walks and five hits in his last two outings covering just two-thirds of an inning.

The biggest disappointment was those outings followed Turnbow's best of the season, a ninth-inning save against Philadelphia on April 23.

Melvin said he had not received any indication from Turnbow as to if he would accept an assignment to the minor leagues. Turnbow has the option to become a free agent after 10 days, but he would forfeit what remains of his $3.2 million a year salary if he should choose that route.

Melvin said he had already heard from two clubs about Turnbow and said he expected to hear from more. However, he also indicated he wouldn't mind if Turnbow accepted the minor-league assignment.

"I'd just like to get him straightened out," Melvin said.

Turnbow was 0-1 with a 15.63 ERA in eight games covering 6 1⁄3 innings. He walked 13 and allowed 12 hits.