Outman had a 3.28 ERA in 31 games with Cleveland. He will be tasked with getting left-handed hitters out, New York manager Joe Girardi said.
"He's a left-handed specialist who has had success," Girardi said. "You look at his numbers versus lefties in Cleveland this year, and it wasn't too bad. He'll get an opportunity to help us."
Outman has held lefties to a .180/.293/.380 batting line this year, and he has enjoyed similar success against lefty hitters over the course of his six Major League seasons.
Chris Toman is a contributor to MLB.com This story was not subject to the approval of Major League Baseball or its clubs.