Mason Geertsen Bio
Mason Geertsen (born April 19, 1995) is a Canadian professional ice hockey player who plays for the Rochester Americans in the American Hockey League (AHL) while under contract to the Buffalo Sabres of the National Hockey League (NHL). A defensive-minded defenceman known for his physicality, Geertsen was selected in the fourth round, 93rd overall, by the Colorado Avalanche in the 2013 NHL Entry Draft. Standing 196 cm tall and weighing 104 kg, he has built a career in professional hockey organizations across North America.
Early Life and Background
Mason Geertsen was born on April 19, 1995, in Drayton Valley, Alberta, Canada. Growing up in a hockey-loving province, he was introduced to the sport at a young age through local youth programs. His size and physical attributes became apparent early in his development, shaping his path as a defenceman.
As a youth, Geertsen played bantam and midget hockey with the Leduc Oil Kings in the Alberta Major Bantam Hockey League and with the Sherwood Park Kings in the Alberta Midget Hockey League. His performance in these leagues caught the attention of scouts, leading to his selection 18th overall in the first round of the 2010 WHL Bantam Draft by the Edmonton Oil Kings of the Western Hockey League (WHL).
Path to Hockey
Joining the Edmonton Oil Kings marked the beginning of Geertsen’s major junior career in the WHL. Over the following seasons, he developed into a physical, stay-at-home defenceman, refining his game against top Western Canadian competition. His progression through the WHL ranks prepared him for the transition to professional hockey.
In 2012, Geertsen represented Canada Pacific at the World U-17 Hockey Challenge in Windsor, Ontario, where he appeared in five games from the blueline in a fifth-place finish. The international experience provided valuable exposure, and his steady development eventually led to his selection by the Colorado Avalanche in the 2013 NHL Entry Draft.
Mason Geertsen Career
Early Career (2015–2017)
Geertsen began his professional career in the Avalanche organization, splitting time between the AHL’s San Antonio Rampage and the ECHL’s Colorado Eagles. Used primarily in a defensive role, he added physicality to the Rampage lineup, appearing in 36 games during the 2016–17 season and recording 4 assists.
He later joined the Colorado Eagles in time for the ECHL postseason, where he established a regular spot on the defence. Recording 1 goal and 4 points in 19 games, Geertsen helped the Eagles capture their first Kelly Cup championship. His tenure with the Avalanche ended on June 25, 2019, when he was not tendered a qualifying offer as a restricted free agent.
Hartford Wolf Pack and New York Rangers Era (2019–2021)
Following his release from Colorado, Geertsen attended the New York Rangers 2019 training camp on a professional tryout. After a successful showing, he was signed to a one-year AHL contract with the Hartford Wolf Pack on September 29, 2019.
During the 2019–20 season, Geertsen established himself as a physical stay-at-home defenceman for the Wolf Pack, appearing in 60 regular season games and leading the club with 109 penalty minutes. On April 23, 2020, he signed a one-year contract extension to remain with the organization. Entering the pandemic-delayed 2020–21 season, he registered one assist through four games before being signed to a two-year, two-way contract with the NHL affiliate, the New York Rangers, on March 4, 2021.
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. During the 2021–22 season, he played 25 games for the Devils before signing a one-year contract extension at league minimum salary on July 13, 2022.
The 2022–23 season saw Geertsen spend the full year with the Devils’ AHL affiliate, the Utica Comets, where he set AHL career highs of 4 goals and 136 penalty minutes. His combination of size and toughness continued to define his role within the organization.
Vegas Golden Knights Era (2023–2025)
As a free agent, Geertsen signed a two-year, two-way contract with the Vegas Golden Knights on July 1, 2023. Throughout the duration of his contract, he played entirely with their AHL affiliate, the Henderson Silver Knights.
Buffalo Sabres Era (2025–Present)
On July 1, 2025, on the first day of free agency, Geertsen was signed to a two-year, two-way contract with the Buffalo Sabres. He was assigned to play for the Rochester Americans, the Sabres’ AHL affiliate, continuing his role as a physical defensive presence.
Driving Style and Strengths
Geertsen is recognized for his physical, stay-at-home style of defence. At 196 cm and 104 kg, he uses his size to disrupt opponents, block shooting lanes, and clear the crease. His willingness to drop the gloves and accumulate penalty minutes makes him a valuable presence on the back end, particularly in a defensive or penalty-killing role.
Notable Events and Milestones
Among the highlights of Geertsen’s career is his contribution to the Colorado Eagles’ first Kelly Cup championship in 2017, where he posted 1 goal and 4 points in 19 postseason games. He also made his NHL debut on October 19, 2021, with the New Jersey Devils against the Seattle Kraken. On November 22, 2024, he publicly announced that he had been diagnosed with non-Hodgkin lymphoma in November 2023 and, after undergoing treatment through the summer of 2024, his cancer went into remission before the 2024–25 season.
Mason Geertsen Career Wins
Geertsen’s most prominent team achievement is helping the Colorado Eagles capture their first Kelly Cup as an ECHL expansion franchise in the 2016–17 season. He has not recorded verified individual championship honours at the AHL or NHL level.
Other Wins & Performances
Beyond the Kelly Cup, Geertsen has posted several personal milestones, including AHL career highs of 4 goals and 136 penalty minutes during the 2022–23 season with the Utica Comets, and leading the Hartford Wolf Pack with 109 penalty minutes in 2019–20. He also represented Canada Pacific at the 2012 World U-17 Hockey Challenge.
Mason Geertsen Family
Family Background and Racing Lineage
Geertsen’s family supported his early hockey development, and he played his bantam and midget hockey in the Alberta amateur system before joining the major junior ranks. He is Canadian by nationality, and his formative years were spent in Alberta, where he built the foundation of his hockey career.
Personal Life
Geertsen has publicly shared his battle with non-Hodgkin lymphoma, announcing his diagnosis in November 2024. After completing treatment through the summer of 2024, he returned to the ice with the Henderson Silver Knights for the 2024–25 season in remission, demonstrating resilience throughout his career.
2025 Season Performance
On July 1, 2025, Geertsen signed a two-year, two-way contract with the Buffalo Sabres and was assigned to the Rochester Americans of the AHL. The move places him within a developing Sabres system focused on size and defensive responsibility on the blue line.
Following his return from cancer treatment, Geertsen brings experience and physicality to the Rochester Americans roster. His role as a veteran presence among younger defencemen is expected to remain central to his contributions during the 2025–26 season.
With his contract extending through the 2026–27 season, Geertsen has the opportunity to continue building his professional resume while serving as a steady, physical presence in the Sabres organization. His story of perseverance following his cancer remission adds an inspirational dimension to his ongoing career.