CINCINNATI -- Reds shortstop Zack Cozart hurt his right knee during the first inning of a game against the Philadelphia Phillies on Wednesday and had to be helped off the field.
Cozart tried to beat out a grounder and stretched his right foot to touch the base. His foot slipped across the base, causing his ankle and knee to twist. He fell to the ground, rolled onto his back and grabbed his right knee immediately, wincing in pain.
He was examined by a trainer and didn't put any weight on the leg as he was helped off the field and taken for an exam.
It's a significant blow to the Reds, who already are missing catcher Devin Mesoraco and starter Homer Bailey. Mesoraco -- an All-Star last season -- needs hip surgery, and Bailey had reconstructive elbow surgery.
Also, left fielder Marlon Byrd is recovering from a broken wrist.
The Reds were 11 games out of first place in the NL Central entering Wednesday.
Cozart is among the NL's top shortstops in numerous offensive categories. He had homered in three of his last four games, leaving him with nine homers and 28 RBI.
He also is the Reds' second-leading vote getter in fan balloting for the All-Star Game that will be played in Cincinnati next month. Only third baseman Todd Frazier has gotten more fan votes.