The Texas Rangers have placed first baseman Mitch Moreland on the disabled list with a strained left hamstring, which is expected to keep him out 4-6 weeks.

Moreland suffered the injury while running to first base in the second inning of Tuesday's 7-3 win over the Padres. In 55 games this year, he is batting .272 with 10 home runs and 25 RBIs

Pitcher Roy Oswalt was activated and will make his debut for Texas Friday night against the Colorado Rockies. The Rangers still have not made a corresponding move on the 40-man roster yet.

The Rangers also announced that television broadcaster Dave Barnett will not work this weekend against the Rockies as he continues to undergo tests and evaluations.