Jae Crowder, Tristan Thompson

FILE: Cleveland Cavaliers' Tristan Thompson (13) drives past Boston Celtics' Jae Crowder (99) during the fourth quarter of a first-round NBA playoff basketball game Tuesday, April 21, 2015, in Cleveland.

(AP Photo/Mark Duncan)

On the first day of the offseason, the Boston Celtics picked up a bit of good news. Forward Jae Crowder is not expected to need surgery after suffering an ugly injury in Sunday's Game 4 loss.

The Celtics announced Monday morning that Crowder has been diagnosed with a sprained left ACL. He told the Boston Globe that he expects to be sidelined for just a few weeks.

During the third quarter of Game 4, Crowder took a swinging elbow from J.R. Smith to the face. While falling to the court from the contact, Crowder injured his left knee. He needed assistance to hobble into the locker room, and did not return to the game.

"Cheap shots," Crowder told the Globe. "But it is what it is."

Crowder's restricted free agency will be one important aspect of the Celtics offseason. Team president of basketball operations Danny Ainge has said he considers the 24-year-old "a part of our team going forward."