Two young starters who have assumed prominent roles in their respective rotations will oppose each other Saturday when the Colorado Rockies and Los Angeles Dodgers continue their series. The Dodgers trail the Rockies by a half game in the National League West after their 4-2 win on Friday. The Arizona Diamondbacks, who beat the Atlanta Braves 5-3 on Friday, are third, 1 1/2 games behind the Rockies.