The Rockies activated left-hander Chris Rusin from the disabled list and optioned right-hander Antonio Senzatela to Triple-A Albuquerque in advance of their three-game series against the Mets in New York, MLB.com's Thomas Harding reported on Friday.
The club has not confirmed the transactions.
With the addition of Rusin, Colorado will have four lefties in its bullpen against the Mets, whose roster has four left-handed hitters and three switch-hitters. Rusin has a 4.97 ERA with 11 strikeouts through 12 2/3 innings in eight big league games this season. The 23-year-old southpaw walked one and struck out four in 1 2/3 innings in his last relief big league appearance against the Cubs on April 22.