The Boston Bruins have some big question marks on their blueline heading into the season. 

Charlie McAvoy and Brandon Carlo both remain without contract and it doesn't sound like things will get done anytime soon. 

To make matters worse, there's no guarantee Zdeno Chara will be ready to start the season and now head coach Bruce Cassidy has confirmed another defenseman will miss the start of the season. 

Cassidy told the media on Monday that John Moore likely won't be around for the start of the season after having shoulder surgery in late June. 

So with McAvoy, Carlo, Chara and Moore all possibly unavailable to start the year, that leaves the team with Torey Krug, Kevan Miller, Matt Grzelcyk, Steven Kampfer and Connor Clifton.

The team has Urho Vaakanainen, Jakub Zboril, Axel Andersson, Wiley Sherman and Jeremy Lauzon available on their entry level contracts.