Rangers third baseman Adrian Beltre will miss an additional three weeks after aggravating the strained left hamstring that landed him on the disabled list in late July.
The All-Star was rounding first base during a running session Saturday when he came up lame and shut down the workout, slapping his head in frustration.
The club announced during the game against the Cleveland Indians later Saturday that an MRI indicated Beltre had done more damage to the hamstring and would miss the additional time.
Beltre has been on the 15-day disabled list since July 23. Saturday was his first attempt at back-to-back sessions.
The Rangers also said right-hander Alexi Ogando was placed on paternity leave to await the birth of his child in the Dominican Republic. To take his place on the active roster, the Rangers recalled righty Darren O'Day from Triple-A Round Rock.
Ogando is expected to return for his scheduled start Tuesday against Seattle. A player can be on the paternity list for a maximum of 72 hours, meaning Ogando would return to the active roster on or before Tuesday's game.
O'Day was on the team's opening day roster before spending more than two months on the disabled list for surgery to repair a partial tear of the labrum in his left hip. He returned July 2.
He is 0-1 with a 4.22 ERA in 11 relief appearances for Texas this season. He was optioned to Round Rock on July 14 and has a 2.79 ERA in eight bullpen outings with the Express.