BOSTON — On June 26, 2025, the Utah Mammoth acquired JJ Peterka from the Buffalo Sabres. The same day, the Mammoth signed the pending restricted free agent to a five-year, $38.5 million contract.One year later, the Mammoth decided Peterka was not in their plans. On Friday, the Boston Bruins were happy to accommodate them.That a player became available just one year after signing a long-term contract is a cautionary sign. So is the fact Peterka joined his third organization in 365 days.But the 24-year-old forward is coming off three straight 25-goal seasons. The Bruins do not have such commodities in abundance. That they didn’t have to trade a roster player to the Mammoth for Peterka was a bonus. The Bruins moved the 2026 No. 23 pick and the 2028 first-rounder (top-10 protected) they acquired from the Florida Panthers in the Brad Marchand trade for Peterka. The left-shot Peterka is a quick and dynamic wing who should supply the Bruins with the top-six speed and skill they targeted this offseason.Peterka, a Munich native, did not play for coach Marco Sturm in international competition. But according to general manager Don Sweeney, Sturm is well aware of Peterka’s game based on personal knowledge and the insight of former colleagues.Sturm has options on deployment. He could use the left-shot Peterka on his strong side on the No. 1 line with David Pastrnak. He could keep Peterka on his off wing on the second line. Wherever Sturm uses Peterka, he will bring an element of pace the Bruins have been lacking.“He’s got an elite shot,” Sweeney said. “Probably gives us another look on the elbows in the power-play situation. His power-play minutes dipped a little bit last year. Five-on-five production has been really good. Plays both wings. Could probably play with a couple different types of centers. Help drive a line, but also complement the better guys in situations we’re certainly trying to improve in.”Peterka scored 25 goals and 47 assists in 82 games in 2025-26 while averaging 15:59 of ice time per appearance. He scored 20 five-on-five goals, second most on the Utah roster after Dylan Guenther. The rush game is central to his offensive portfolio. The Bruins are eager to introduce more transition production.Peterka averaged 1:57 of power-play time per game, mostly on Utah’s No. 2 unit. He did not kill penalties.Peterka has four years remaining on his contract at $7.7 million annually. He was originally a second-round pick of the Buffalo Sabres in 2020. Peterka scored a career-high 68 points for the Sabres while averaging 18:11 of ice time per outing before moving to the Mammoth.The Sabres traded Peterka to the Mammoth for Josh Doan and Michael Kesselring. He took a step back in production and workload as a first-year Mammoth. He sent up a red flag in the playoffs by going without a point against the Vegas Golden Knights. Peterka slipped behind some of the Mammoth’s skilled forwards: Guenther, Logan Cooley, Clayton Keller and Nick Schmaltz.“They were a young group, and he was asked to drive a lot of offense. He has the ability to do that,” Sweeney said of Peterka’s 2024-25 production with the Sabres.“He became a little more complementary,” Sweeney added, describing Peterka’s role in Utah, “because they were a little top-heavy and had a lot of skill there.”Introducing Peterka’s AAV cap hit to the payroll leaves Sweeney with fewer dollars to spend on Viktor Arvidsson, who will be a free agent July 1. It remains to be seen whether the Bruins can re-sign the right wing.By checking the forward box, the Bruins can focus on the right side of the defense. Sweeney is open to the trade market. He can also look at players such as Rasmus Andersson in free agency, although the Peterka commitment leaves the Bruins with less available cash.“We can leave it as is,” Sweeney said. “But that’s not how we’re wired and how we’re built.”