Tonight's game will be shown in the Blues viewing area on FoxSports Midwest, by virtue of tonight being an off-night for the Cardinals. It will also be broadcast on KMOX, 1120 AM, and will be streamed on their website and on the Blues' official website.
Tonight's game will also be broadcast on NBCSN; no word if it will be one of their broadcast crews or if they will be picking up the CSN Chicago broadcast again. Considering it's a potential elimination situation, I would assume that it's a NBC crew.
If you're not home to watch the game, you can watch it via NBCSN's Live Extra app and website. The game should kick up at puck drop, but may be blacked out in the metro St. Louis area due to FSMW's broadcast rights.You can view the stream here.