CALGARY — Dion Phaneuf is known for his hellacious hits, but this time it’s the Calgary Flames’ defense corps that may be absorbing a body blow.

Phaneuf, the hard-hitting former Norris Trophy finalist, was knocked out of Saturday’s Game 5 of this Western Conference Quarterfinal after a third-period, helmet-on-helmet collision with Chicago’s Troy Brouwer.

Phaneuf was nowhere to be seen following the Flames’ off-ice training session Sunday afternoon at the Pengrowth Saddledome, and Calgary head coach Mike Keenan wasn’t revealing much about his status.

"It’s the same thing we tell you about every other injured player," Keenan told reporters. "He’s day to day."

Phaneuf had just followed through with a shot during Saturday’s 5-1 loss to the Blackhawks when he was leveled by Brouwer. The head-on-head impact left Phaneuf visibly woozy, and he departed the United Center’s ice surface immediately.

The Flames are already trailing this best-of-7, first-round NHL playoff series three games to two, with their season on the line Monday night during Game 6 (9:30 p.m. ET, TSN). Playing without Phaneuf would be a hard pill to swallow for Calgary’s already battered blue line.

Shut-down specialist Robyn Regehr, the cornerstone of the Flames’ defense, hasn’t played since April 2 in Dallas with a lower-body injury.

Meanwhile, fellow defenseman Cory Sarich has been gutting it out on a sore foot after returning to action in Game 2 of this series.

"Hopefully, Dion is back and feeling great for next game," captain Jarome Iginla said. "But if he’s not, we still need to find a way to win the game.

"It’s been a physical series, and we do have depth. We’ve talked about it all year, (and) we need it now.

"The other thing," added Iginla, "is that we believe we’ll get past this, and we’re also getting some big guys back."

Should Phaneuf be unable to answer the bell Monday, veteran defenseman Anders Eriksson, who was called up from Quad Cities of the AHL at the end of the regular season, is expected to fill in.

Prior to Game 5, Phaneuf had a plus-3 rating with three assists in this series against the Blackhawks, rebounding from a forgettable regular season.

 "You want to be a plus player, and that’s definitely a big part of being good defensively," Phaneuf, 24, had told reporters in Chicago. "(But) personal statistics don’t really matter. This time of year it doesn’t matter."