Mrazek (groin) was activated from injured reserve Thursday, Charlie Roumeliotis of WGN Radio reports.
The Chicago netminder missed the last five games with the injury. Mrazek is 7-11-1 with a 2.83 GAA and a .906 save percentage across 20 appearances this season. He is in line to get the start versus Seattle on Thursday. The Blackhawks sent Drew Commesso to AHL Rockford in a corresponding move.