Rosin is a Rule 5 Draft pick claimed on waivers last Wednesday from the Dodgers. He has to stay on the Major League roster for the whole year or be offered back to his original team, the Phillies, for $25,000. He pitched a scoreless inning against the Astros on Saturday and two against the Quinana Roo Tigers on Thursday.
"We're still watching him," manager Ron Washington said. "He's getting outs. He's showing a good slider and keeping the ball down in the zone. We're hoping he can continue to get outs."
The Rangers have sent pitchers Ryan Feierabend, Daniel McCutchen and Justin Germano to Triple-A Round Rock. Colby Lewis has also been officially assigned to Round Rock.
T.R. Sullivan is a reporter for MLB.com. Read his blog, Postcards from Elysian Fields, and follow him on Twitter @Sullivan_Ranger. This story was not subject to the approval of Major League Baseball or its clubs.