The Rangers activated Curvelo (shoulder) from the 15-day injured list Wednesday and optioned him to Triple-A Round Rock.
Curvelo has been shelved since mid-April with a right shoulder impingement, but he recently made a couple scoreless rehab appearances with Round Rock despite three walks. Rather than add him back to the major-league bullpen, the Rangers have elected to keep Curvelo in the minors for the time being.