According to MLB.com's T.R. Sullivan the Rangers acquired pitcher Jason Grilli from the Rockies. He was designated for assignment on Friday after allowing more than two baserunners per frame over the course of 19.1 innings with the Rockies. Grilli, who did strike out 22 batters, was obtained for cash considerations.
The Rangers have been looking for relievers, and while they're likely not finished, this move gives them depth. Yet another reason to follow MLBTR on Twitter: we reported speculation about this move on Twitter yesterday.