Chamberlain, who has been on the disabled list since May 2 after sustaining an oblique strain during pregame warmups on April 28, had a 3.86 ERA over 9 1/3 innings before the injury.
He joins a bullpen that has performed very well of late, despite David Robertson's loss Monday night. Entering Tuesday, Robertson has a 3.00 ERA, Boone Logan hasn't allowed a run in 10 straight appearances, Shawn Kelley has given up just three runs in May after struggling in April and Adam Warren and Preston Claiborne both have ERAs under 1.15.
Chamberlain said he doesn't know yet what his role is going to be, but he said his experience in a lot of different situations should work to his advantage.
"Everybody is throwing the ball well," Chamberlain said. "Just to be in the mix with those guys down there has been fun to watch, and now to be a part of it is going to be even better."
David Huff was designated for assignment to make room for Chamberlain. The Yankees claimed Huff off waivers from the Indians just three days ago. He made only one appearance with the team, allowing a run in Sunday's loss to the Rays.
There was some speculation that the Yankees might send down Ivan Nova so he could get stretched out again as a starter, but Girardi said the team kept him on the roster due to concerns with this week's weather.
"With what we went through with [Hiroki] Kuroda and [David] Phelps, we want all the pitching we can here," Girardi said. "I know you can say we're a little bit shorthanded in a National League ballpark, but we'll make that work."
Bryan Hoch is a reporter for MLB.com. Follow him on Twitter @bryanhoch and read his MLBlog, Bombers Beat. Josh Vitale is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.