Postava was called up from AHL Grand Rapids on Thursday under emergency conditions.
Postava has a 1.86 GAA and a .932 save percentage in 21 outings with Grand Rapids this season. He hasn't made his NHL debut yet. Cam Talbot (undisclosed) won't be available for Friday's road game against Buffalo, so Postava or John Gibson will get the start with the other netminder serving as the understudy.