The Boston Bruins and general manager Don Sweeney don't have the biggest amount of cap space this off season. 

The team will have enough room to possibly sign an older forward who can skate with David Krejci. 

Lots of analysts have suggested that the Bruins find a way to trade David Backes or buy him out. 

A trade is unlikely and there's probably no way that Sweeney throws in a first round pick like the Leafs did to move Patrick Marleau out of Toronto. 

While doing some digging Fluto Shinzawa spoke to people around the league about Backes and one assistant GM said it would be "impossible to move" Backes and his contract and "a trade would require a high end pick plus a prospect". 

So not only would the Bruins have to throw in a high pick like Toronto did with Carolina, but they'd also have to throw in a prospect!

With a statement like that, you can expect Backes to be around until his contract is over. 

Source: The Athletic