Mason Geertsen Bio
Mason Geertsen (born April 19, 1995) is a Canadian professional ice hockey player for the Rochester Americans in the American Hockey League while under contract to the Buffalo Sabres of the National Hockey League. A fourth-round selection, 93rd overall, by the Colorado Avalanche at the 2013 NHL Entry Draft, Geertsen is known for his size, physical play and role as a stay-at-home defender.
Early Life and Background
Mason Geertsen was born in Drayton Valley, Alberta, Canada, on April 19, 1995. He came through Alberta’s youth hockey system, playing bantam hockey with the Leduc Oil Kings in the Alberta Major Bantam Hockey League and midget hockey with the Sherwood Park Kings in the Alberta Midget Hockey League.
Geertsen’s major junior career began after he was selected 18th overall in the 2010 Western Hockey League Bantam Draft by the Edmonton Oil Kings. His size and physical style were evident early and shaped his path to professional hockey, where he developed as a defensive specialist and enforcer-type presence on the blueline.
Path to Hockey
Geertsen progressed from Alberta minor hockey into the Western Hockey League with the Edmonton Oil Kings, using his frame and physicality to draw attention from NHL scouts. His play in major junior led to his selection in the 2013 NHL Entry Draft, when the Colorado Avalanche chose him in the fourth round.
After his time in the WHL, Geertsen moved into professional ranks beginning in 2015. He worked through the Avalanche organization’s development pipeline, spending time in the American Hockey League and the ECHL while establishing a reputation as a physical, defensively focused player who brought penalty-minute and toughness metrics to his teams.
Mason Geertsen Career
Early Career (2015–2017)
Geertsen turned professional in 2015 and split time between Avalanche-affiliated clubs in the AHL and ECHL as he adapted to the pro game. During the 2016–17 season he was assigned to the San Antonio Rampage and saw regular action as a defensive, physical presence. He spent parts of that season with the Colorado Eagles, Colorado’s secondary affiliate, and played through the postseason.
With the Colorado Eagles Geertsen carved out a regular role on the defence during their playoff run, recording one goal and four points in 19 postseason games and helping the club capture its first Kelly Cup. That postseason experience marked an early career milestone and underscored his value as a depth defender in playoff environments.
AHL and NHL Breakthrough (2019–2021)
Following the conclusion of his entry-level contract, Geertsen was not tendered a qualifying offer by the Colorado Avalanche in June 2019 and became a free agent. He attended the New York Rangers 2019 training camp and, after being released in the second round of cuts, signed a one-year AHL contract with the Hartford Wolf Pack on September 29, 2019.
Geertsen established himself within the Wolf Pack blueline during the 2019–20 season, appearing in 60 regular-season games and leading the team with 109 penalty minutes before the season was cancelled due to the COVID-19 pandemic. He was retained by Hartford with a one-year extension in April 2020, and his role as a stay-at-home, physical defenceman continued to define his AHL contributions.
In the pandemic-delayed 2020–21 season Geertsen registered an assist through four games before signing a two-year, two-way NHL contract with the New York Rangers on March 4, 2021. That contract paved the way for NHL opportunity and broader organizational depth responsibilities.
New Jersey Devils Era (2021–2023)
On October 3, 2021, Geertsen was claimed off waivers by the New Jersey Devils. He made his NHL debut on October 19, 2021, in a game against the Seattle Kraken and appeared in 25 NHL games that season, contributing size and physicality to New Jersey’s lineup when called upon.
Geertsen signed a one-year contract extension with the Devils on July 13, 2022, then spent the 2022–23 season with New Jersey’s AHL affiliate, the Utica Comets. In Utica he set AHL career highs with four goals and 136 penalty minutes, reinforcing his profile as a physical, defensive-minded blueliner at the AHL level.
Vegas Golden Knights and Henderson Silver Knights (2023–2024)
As a free agent from the Devils, Geertsen signed a two-year, two-way contract with the Vegas Golden Knights on July 1, 2023. During the term of that contract he played the entirety of his time with the Henderson Silver Knights, Vegas’s AHL affiliate, providing veteran physical presence and organizational depth on the blueline.
Buffalo Sabres / Rochester Americans Era (2025–Present)
On July 1, 2025 Geertsen was signed to a two-year, two-way contract with the Buffalo Sabres. He is listed with the Rochester Americans in the American Hockey League while under contract to Buffalo, continuing his role as a depth defender and physical option for call-up situations.
Entering the contract with Buffalo, Geertsen brings extended AHL experience and prior NHL appearances. His role with Rochester centers on defensive zone coverage, physical deterrence, and veteran presence for a club balancing player development and competitive AHL play.
Playing Style and Strengths
Geertsen is a left-shot, 6-foot-5, 230-pound defender who plays a stay-at-home, physical game. He is valued for reach, board play, clearing the front of the net, and penalty-killing minutes, using size and toughness to deter opposition forechecking while maintaining a conservative defensive posture.
Notable Events and Milestones
Key milestones in Geertsen’s career include his selection by the Colorado Avalanche in the 2013 NHL Entry Draft, helping the Colorado Eagles capture their first Kelly Cup in the 2016–17 postseason, his NHL debut for the New Jersey Devils on October 19, 2021, and reaching AHL career-high offensive and penalty-minute totals with the Utica Comets in 2022–23.
Mason Geertsen Family
Family Background and Racing Lineage
Geertsen was raised in Drayton Valley, Alberta. Public records and available biographies emphasize his development through Alberta’s minor hockey programs; no additional family or lineage details are listed in the provided sources.
Personal Life
In public statements reported by available sources, Geertsen disclosed a diagnosis of non-Hodgkin lymphoma in November 2023, which led to a one-month absence during the 2023–24 season. After treatment through the summer of 2024 his cancer went into remission before the 2024–25 season, and he returned to professional play.
2025 Season Performance
For 2025 Geertsen is under contract to the Buffalo Sabres and rostered with the Rochester Americans in the AHL. His expected role centers on defensive responsibility, physical on-ice presence and serving as a call-up option for the Sabres when roster depth is required.
Geertsen’s 2025 outlook is built on extensive AHL experience, prior NHL appearances and a demonstrated role as a stay-at-home defender. His responsibilities with Rochester include penalty killing, heavy minutes in defensive zone situations and mentoring younger blueliners on physical aspects of pro hockey.