The Bruins will be relying on their defensive depth to get them through McAvoy's absence. In recent weeks, Boston's back end has played so well that Cassidy has at times been forced to scratch veterans Adam McQuaid and Kevan Miller. With McAvoy out, both blue liners will be in the lineup against the New Jersey Devils on Tuesday night.
"We've always said, a good problem to have as a coach is to have too many good players," said Cassidy. "When you don't have enough good players that's a bad problem to have. For us to have what we believe are eight defensemen that can play in the National Hockey League at any time - we'll adjust the pairs to what suits us, but we've got six guys we're real comfortable with tonight.
"That's what you need to win. It's nice to have Kevan back and feeling good and healthy and ready to go…he was playing very well before he got ill. We expect a good game from the D corps, no matter who the partners are. They're six good players - 'Play to your strengths, play well,' and I think we'll be fine."
Cassidy confirmed that Miller - who has missed the last three games - will slide back in alongside Grzelcyk on Boston's third pairing, while Adam McQuaid will reunite with Torey Krug and Brandon Carlo with Zdeno Chara.
"We're going to stick with that. There's continuity in terms of them all playing together at some point," said Cassidy. "A lot of it was last year, Krug-McQuaid, Zee-Carlo…Grizz and Miller have been together all year. We'll see how it works out. We can always move Kevan up with Zee if need be or Adam if we see something that's not working out, but that's how we'll start it."