Today was the deadline for Salary Arbitration, and the NHLPA announced around 40 players who will be taking part in such hearings:
The Bruins only have one player set for arbitration this year: Danton Heinen. The date of the arbitration hearing is unknown as of this time.
The chances of this being some long dramatic odyssey are extremely slim: almost 90% of all arbitration cases were settled last year before the hearing ever happened. They'll probably figure this out by August.
Until then, we'll keep you posted on how he signs.