Brewers pitcher Yovani Gallardo has a torn anterior cruciate ligament in his right knee and will be sidelined most, if not all, of the season.

Gallardo suffered the injury when he collided with Chicago's Reed Johnson near first base during the fifth inning of his start Thursday afternoon at Wrigley Field. The knee hypextended on the play. Alhough Gallardo remained in the game, an examination this morning revealed the injury and he was placed on the 15-day disabled list.

The Brewers recalled right-hander Dave Bush from Class AAA Nashville to replace Gallardo on the roster.

Gallardo likely will undergo surgery on the knee, which is his "drive" leg as he delivers the baseball. Gallardo missed much of spring training and the first three weeks of the season after undergoing surgery to repair torn cartilage in his left knee.