DENVER -- Nick Masset's struggles commanding the strike zone didn't cost the Rockies a win Saturday, but it might cost him some time after he left the game with left knee injury.

It occurred on a passed ball in the seventh inning, after Masset entered to protect an 8-2 lead. Wilin Rosario's misplay with Hanley Ramirez at the plate permitted Clint Robinson to score from third for the Dodgers' third run of the inning.

Rockies manager Walt Weiss was unclear if Masset hurt his knee planting on that pitch or running to cover home. Regardless, he was escorted off by a trainer and was sent for an MRI following the Rockies' 8-7 victory.

Masset had been one of the better pitchers in a beleaguered bullpen this season, having surrendered nine earned runs over 23 2/3 innings with 18 strikeouts. He departed Saturday's appearance without recording an out, however, and Boone Logan permitted the inherited runner to score, bumping Masset's season ERA up to 4.94 from 3.42.