If the Bruins do let Jake DeBrusk walk in free agency, they will need to find someone to replace him, and it won't be easy, but recently the Bruins have been linked to a former Boston Bruins player in Reilly Smith.
Reilly Smith played two seasons with the Boston Bruins in 2013-14 and 2014-15, before going to the Florida Panthers and then the Vegas Golden Knights where he would end up winning a Stanley Cup, and is now with the Pittsburgh Penguins.
This is what the Bruins are missing and want to address in free agency this year, although if they were to try and re-acquire Smith it would have to be via a trade as he has one year left on his deal at $5 million.