Rosin is 2-1 with a 2.65 ERA in 26 appearances with Lehigh Valley. The Phillies acquired him in July 2012 as part of the Hunter Pence trade with the Giants. The Rangers selected him in the Rule 5 Draft in 2014 and he made three appearances with them, but he ultimately returned to the Phillies.
In Saturday's 10-1 loss to the Cardinals, Rosin allowed five runs on seven hits and a walk over two innings of relief.
Phillies manager Ryne Sandberg said Rosin, 26, can provide the Phillies multiple innings, if needed. He also said Rosin could stick with the Phillies for more a bit.
The Phillies need to make room on the roster for left-hander Adam Morgan, who starts Sunday, but they have not announced that move.