Boston Bruins head coach Bruce Cassidy said Wednesday that defenceman Zdeno Chara did not practice and had no update on his injury sustained in Game 4.

"He's not here and didn't skate, so that makes it a little more difficult for him [to play]," Cassidy told reporters Wednesday.

 A report Tuesday from The Athletic's Jeremy Rutherford indicated that Chara suffered a broken jaw.

Chara returned to the bench in the third period of Game 4 sporting a full cage after taking a shot to the mouth from Blues centre Brayden Schenn early in the second period. He did not play a shift in the final frame and Cassidy said after the team's captain was “advised not to return” to Game 4.

Meanwhile, defenceman Matt Grzelcyk is still in concussion protocol, although he could perhaps be cleared on Thursday according to Cassidy.

Grzelcyk has been out since Game 2 after taking a hit from St. Louis' Oskar Sundqvist, who was suspended one game by the league's Department of Player Safety.

Game 5 will go from Boston Thursday night and then shift back to St. Louis for Game 6 on Sunday.