Patrice Bergeron, Jonathan Toews lost to injury in Game 5 (Video)

CHICAGO -- The Stanley Cup Final is turning into a war of attrition.

Both the Boston Bruins and Chicago Blackhawks each lost two key players in Game 5, which was won by the Blackhawks 3-1.

Chasing after a puck in the Blackhawks' zone, Bergeron appeared to pull up with what looked like an upper-body injury. CBC's Scott Oake reported that the Bruins forward walked to an ambulance under his own power and was taken to a local hospital for further observation.

Bruins head coach Claude Julien had no update on Bergeron's condition after the game.

Sportsnet's Nick Kypreos is reporting that Bergeron may suffered a spleen injury.

On the Blackhawks' side, midway through the second period, with Chicago holding a 2-0 lead, Toews cut across the Bruins' zone on a scoring chance and was met from behind by Johnny Boychuk:

Toews played for the remainder of the second period, but did not in the final 20 minutes of the game despite being present on the Blackhawks' bench. Afterward, head coach Joel Quennville said Toews was "day-to-day" with an upper-body injury.

The hit also raised some eyebrows and the topic of possible supplemental discipline was brought up. The NHL's Department of Player Safety reviews every hit, so this one will be looked at by Brendan Shanahan and his crew closely.

Boychuk's hit was very similar to the one Rick Nash laid on Tomas Kopecky back in March, one that ended without any punishment. If history is any clue, Boychuk will be in the lineup for Game 6 Monday night.

Follow Sean Leahy on Twitter at @Sean_Leahy