Rockies shortstop Troy Tulowitzki left the team's game against the Reds on Monday with a strained lower back. He left the game after hitting an RBI single in the seventh inning. Colorado went on to win 4-3, helping bring the Rockies to within 3 1/2 games of the Dodgers in the NL West. Colorado leads the Wild Card race, holding a two-game edge over San Francisco.