|No. 45 Toronto Argonauts|
|Born:||January 19, 1997|
|Height||6 ft 4 in (193 cm)|
|Weight||240 lb (110 kg)|
|High school||Canada Prep Academy|
Lorne Park Secondary
|CFL Draft||2020 / Round: 2 / Pick: 11|
|Drafted by||Toronto Argonauts|
|Career highlights and awards|
|Honours||First Team All-Canadian|
Cassar played U Sports football for the Carleton Ravens from 2016 to 2019. He played in 31 regular season games where he had 153.5 tackles, eight sacks, and one interception. He was named a U Sports First Team All-Canadian and the OUA Stand-up Defensive Player of the Year in 2019 as he played in seven games where he had 44 tackles, four sacks, seven tackles for a loss, and one fumble recovery.
Cassar was drafted in the second round, 11th overall, in the 2020 CFL Draft by the Toronto Argonauts, but did not play in 2020 due to the cancellation of the 2020 CFL season. He then signed with the team on March 25, 2021. Cassar made the team following training camp and played in his first career professional game on August 7, 2021, against the Calgary Stampeders. However, he suffered a hip injury in that game and was placed on the team's six-game injured list. He returned to play on October 6, 2021, against the Ottawa Redblacks, where he earned his first professional start at middle linebacker, in just his second professional game.
- "Carleton's Trevor Hoyte, Alain Cimankinda selected in CFL draft". The Charlatan. May 22, 2021.
- "Trevor Hoyte". Toronto Argonauts. Retrieved November 9, 2021.
- "Cassar takes home Oustanding Stand-up Defensive Player award". Carleton Ravens. November 7, 2019.
- "Argos sign 11th overall pick Cassar". Toronto Argonauts. March 25, 2021.
- "Former Ravens Cassar and Hoyte make CFL debut for Argos". Carleton Ravens. August 13, 2021.
- Zicarelli, Frank (October 5, 2021). "Argos rookie Cassar 'ready to fly around' in home debut". Toronto Sun.
- Baines, Tim (May 11, 2020). "JUST LIKE MIKE? Comparison to O'Shea aside, Jack Cassar looking to make CFL impact". Ottawa Sun.