The Bruins lineup should look a little different when the Stanley Cup Final shifts to St. Louis this weekend.

B's defenseman Matt Grzelcyk is in the league's concussion protocol after a big hit from the Blues' Oskar Sundqvist sent him into the boards face-first Wednesday night. Grzelcyk did not travel to St. Louis with his teammates Thursday, and while head coach Bruce Cassidy would only go as far as calling Grzelcyk day-to-day, he will likely miss at least Game 3, and possibly even more time.

So where does Boston go from here?

Their depth has been well documented in the Stanley Cup Playoffs, as 14 different forwards and eight different defensemen seeing action — and 19 of those 22 players have scored at least one goal. And though Cassidy has typically gone with the same six blue-liners, both John Moore (five games) and Steven Kampfer (two games) have slotted into the lineup.

The Bruins have a couple days to figure out who could replace Grzelcyk while he's out, and in advance of Friday's practice when we'll get a better look at who's on the ice, DJ Bean looks at the fallout from the Grzelcyk injury.

Click here for DJ's thoughts on how the Bruins could replace Grzelcyk.>>>>

Click here to download the new MyTeams App by NBC Sports! Receive comprehensive coverage of your teams and stream the Celtics easily on your device.