Amateur In 2015, Allison committed to playing
college ice hockey at
Western Michigan University. He drew attention in his freshman year in the
Broncos program, finishing his season with 29 points on 12 goals and 17 assists, as well as a playoff appearance. On December 9, 2017, Allison netted his second
hat trick of the
2017–18 season, becoming one of two NCAA players to score multiple hat tricks that season. On January 13, 2018, Allison suffered an
anterior cruciate ligament injury in a game against
St. Cloud State University, and did not return to play until midway through his junior year. During the
2019–20 season, Allison was named as an
alternate captain for the Broncos. Later that season, Allison suffered a shoulder injury, and only appeared in 26 games, over the course of which he scored 10 goals and 23 points. While the Broncos qualified for the
2020 NCHC Tournament, all playoff games were canceled on March 12, 2020, due to the
COVID-19 pandemic.
Professional Philadelphia Flyers (2020–2024) On June 25, 2016, Allison was selected in the second round of the
2016 NHL entry draft, 52nd overall, by the
Philadelphia Flyers. He was given the option to begin professional hockey before completing his college career, but elected to continue playing at WMU, citing a desire to monitor his ACL injury, as well as a perceived opportunity to play in the
NCAA Division I Men's Ice Hockey Tournament. On March 27, 2020, the Flyers signed Allison to an entry-level contract. Allison suffered an undisclosed injury during the Flyers training camp and started the
2020–21 season on the injury reserve. Allison made his NHL debut on April 15, 2021, against the
Pittsburgh Penguins. He scored his first NHL goal in the next game, on April 17, in a 6–3 loss against the
Washington Capitals.
Nashville Predators (2024) On March 8, 2024, the Flyers traded Allison to the
Nashville Predators in exchange for
Denis Gurianov. He did not feature in a game with the Predators, playing out the season with AHL affiliate, the
Milwaukee Admirals, posting three goals and five points through 14 regular season games.
Barys Astana (2024) Released as a free agent by the Predators, Allison signed his first contract abroad in agreeing to a one-year deal with
Barys Astana of the
Kontinental Hockey League (KHL) on July 12, 2024. In the
2024–25 season, Allison made just 12 appearances with Barys in registering only two goals, before he mutually agreed to terminate the remainder his contract on November 4.
Straubing Tigers (2025–present) On September 13, 2025, the
Straubing Tigers of the
Deutsche Eishockey Liga (DEL) signed Allison to a contract for the
2025–26 season. ==Playing style==