On December 18, 2013, the Bruins recalled Warsofsky from Providence.[9] He is the first Bruin to wear the number 79.[10] He made his NHL debut the following night in a 4–2 loss to the Buffalo Sabres.[11] On December 28, Warsofsky scored his first career NHL goal in a 4–3 loss to the Ottawa Senators.[12] He finished the season with two points in six games for Boston, as well as 32 in 56 with Providence.
On July 1, 2015, Warsofsky signed a one-year, two-way contract with the Pittsburgh Penguins.[13] He skated in 12 games for the Penguins during the 2015–16 season, recording one goal. On February 26, 2016, the New Jersey Devils claimed Warsofsky off waivers.[14] He finished the season with one assist in ten games for the Devils.
On July 1, 2016, Warsofsky returned to the Penguins, signing a one-year, two-way contract.[15] He spent the majority of the 2016–17 season with Wilkes-Barre, where he led all team defensemen with 47 points in 58 contests, all career-highs. He also skated in seven games with Pittsburgh, recording one assist.
On July 1, 2019, Warsofsky returned to the Penguins for a second time, signing a two-year, two-way contract.[17] He was named captain of Wilkes-Barre/Scranton,[18] and led the defense with 33 points in 51 games.
On February 15, 2021, Warsofsky was traded to the Carolina Hurricanes along with Yegor Korshkov in exchange for Alex Galchenyuk.[20] In the 2020–21 season, the Hurricanes assigned Warsofsky to join AHL affiliate, the Chicago Wolves, to be coached by his brother Ryan. Limited to 22 regular season games, he produced 17 assists and 19 points.
A free agent from the Hurricanes, Warsofsky left North America by signing his first contract abroad, agreeing to a one-year contract with German club ERC Ingolstadt of the DEL on June 18, 2021.[21]