Hayes passed away at the age of 31, Sportsnet reported Monday.
Hayes signed a one-year, two-way contract with Pittsburgh.
Hayes skated in 33 games in the 2017-18 season, scoring three goals and collecting six assists while averaging 11:53 of ice time.
Hayes, who has completed his conditioning assignment, received a call-up from AHL Albany on Thursday.
Hayes was a healthy scratch during a 5-4 shootout loss to the Islanders on Sunday.
Hayes, a frequent bench warmer, will play Saturday against the Coyotes, Devils' beat writer Amanda Stein reports.
Hayes has earned himself a one-year, one-way contract worth $700,000, Bob McKenzie of TSN reports.
Hayes will attend Devils' training camp on a professional tryout agreement, Mark Divver of The Providence Journal reports.
The Bruins have placed Hayes on waivers for the purpose of a buyout, the team's official site reports.
Hayes (lower body) is not in line to suit up for Wednesday's playoff opener against Ottawa.