Frieri pitched for Colombia in the World Baseball Classic.
"This is a guy that saved a lot of games," Girardi said after Wednesday night's 3-1 win over Philadelphia. "He pitched well in the WBC. Some of our people saw him and he's going to get an opportunity here."
The 31-year-old Frieri had 37 saves for the Angels in 2013. The right-hander last pitched in the majors with Tampa Bay in 2015.
Also, backup catcher Austin Romine left in the seventh inning after a wild pitch struck his right hand. The team said X-rays were negative