An injury to starter Matt Harrison dampened the mood of what was otherwise a good Sunday night for the Texas Rangers.Leonys Martin had a double, a triple and three RBIs and Elvis Andrus reached base four times in a 4-2 Texas Rangers victory against the Colorado Rockies to conclude another series triumph in front of a club-record 22nd sellout crowd at Rangers Ballpark in Arlington.Harrison left the game with lower back stiffness after pitching five innings, giving up five hits and two walks and striking out three. The left-hander later said he fully intended to make his next start.He improved to 6-0 with a 1.29 ERA in his last seven starts, but the possibility of yet another starter going down overshadowed those encouraging trends.The Rangers have sent four pitchers, including starters Neftali Feliz and Derek Holland, to the disabled list the past six weeks. Alexi Ogando, making a start in place of Holland, was injured running out a ground ball as a hitter in San Francisco. Reliever Koji Uehara is also on the DL.Harrison was examined by team doctor Keith Meister and was given a preliminary diagnosis of stiffness in the lower back. He will be re-examined in the coming days.The Rangers got all the offense they needed in the second and third innings.Martin's two-out double scored Nelson Cruz to give the Rangers a one-run lead in the bottom of the second, followed two batters later by Andrus' double that scored Martin.A two-out triple by Martin who was making his third start since being called up from Triple-A Round Rock on June 15 in the third brought home Cruz and Michael Young, who led off the inning with a single and advanced to second on a walk to Cruz.Andrus was 3-for-4 with two doubles and a single. He reached base a fourth time with a walk in the ninth.Robbie Ross, Tanner Scheppers and Mike Adams pitched three innings of scoreless relief.Closer Joe Nathan got into trouble in the ninth, giving up two runs on a single, a walk and a hit batter. Marco Scutaro's run-scoring single and Carlos Gonzalez's sacrifice fly accounted for the Rockies runs.Nathan finally finished off the Rockies by striking out Jason Giambi to end the game. The Rockies' runs represented the first given up by Nathan since May 13, a stretch of 16 scoreless innings.Alex White, who gave up all of the Rangers runs in 2 2/3 innings, was charged with the loss for Colorado.