This is being reported on Scout's Cleveland Cavaliers forum, via radio reports on WKNR. It's apparently a left foot sprain.
Pavlovic has struggled a bit this season after missing the Cavs pre-season. His scoring average has dropped about two points a game from 2006, but he seemed to be coming back a bit.
Here's a link from RealGM.com as well:
Pavlovic Out 6 To 8 Weeks With Foot Injury