McAvoy was suspended after the Bruins were eliminated from the playoffs last season for slashing Zach Benson in Game 6. McAvoy's absence means room for a young defenseman to crack the opening night roster like Frederic Brunet, who worked on PP2 on Tuesday. McAvoy will be eligible to return to the lineup in San Jose on October 13th.
Boston solidified some offensive depth on Thursday after they announced they had signed Providence (AHL) forward Riley Duran to a one-year, two-way contract. The 24-year-old joined Boston's organization from Providence College (NCAA) in 2023-24 and has appeared in 132 games with the Providence Bruins (AHL) across the last two seasons. He made his NHL debut last season, failing to pick up a point across two appearances.
Injuries have afforded Patera a few looks at NHL exposure over the past few seasons, but none have stuck. The 27-year-old goalie spent most of 2025-26 in the AHL, where he posted a 2.63 GAA and .910 SV% in 30 games (12-14-2) with the Abbotsford Canucks.
Halonen had a 15-game stint with the New Jersey Devils last season, a career-high, scoring two points (1G / 1A). That said, the undrafted 27-year-old forward spent most of 2025-26 in the AHL, where he scored 34 points (20G / 14A) in 51 games with the Utica Comets.
Guenette was drafted in the seventh round by the Ottawa Senators in the 2019 NHL Entry Draft. He has primarily played in the AHL, including scoring 24 points (2G / 22A) last season in 46 games with the Lehigh Valley Phantoms.
Gaunce was drafted 26th overall in the 2012 NHL Entry Draft by the Vancouver Canucks, but never really transitioned into a regular NHLer. That said, the 32-year-old forward has 35 points (15G / 20A) in 214 career NHL games. He spent most of the 2025-26 season in the AHL, scoring 36 points (16G / 20A) in 44 games with the Cleveland Monsters.
Borgen has become a reliable bottom-four defenseman in recent seasons and will bring his talents to the Boston Bruins after being acquired in a trade. The 29-year-old Borgen averaged 18:03 time-on-ice, recording 15 points (5G / 10A) and a +3 plus/minus in 75 games last season.
Harris' 2025-26 season was hampered by injuries, as he played just eight games with Boston and four with Providence (AHL), but he impressed the organization enough to earn a one-year contract extension. The 25-year-old defenseman, a third-round pick in the 2018 NHL Entry Draft, has 40 points (10G / 30A) in 172 career NHL games.
Clifton made his NHL debut in the 2018-19 season with the Boston Bruins, playing five seasons with the team, and will rejoin them after three seasons away. The 30-year-old defenseman spent the 2025-26 season with the Pittsburgh Penguins, recording six points (2G / 4A) and 180 hits in 50 games.
Vaisanen was drafted in the fourth round of the 2021 NHL Entry Draft by the New York Rangers, but he has yet to make his NHL debut. The 23-year-old forward spent his first full professional season in North America, recording four points (3G / 1A) in 51 games with the Hartford Wolf Pack.
Boston has locked up some goaltending depth after it was announced Wednesday that Luke Cavallin had signed a one-year, two-way contract. The 25-year-old undrafted German net-minder appeared in Providence (AHL) for eight games in 2025-26 but spent the majority of the season with Maine (ECHL), where he had a 18-10-5 record, .917 SV% and 2.35 GAA.
