After two years with the National Team Development Program (USNTDP), Farrell began playing in the United States Hockey League (USHL) with the Chicago Steel.

[6] He made his NHL debut two days later in a game against the Philadelphia Flyers whereas his first goal came on his first shot in the league in a 5–2 loss to the Florida Panthers on March 30.

[7] After attending the ensuing training camp with the Canadiens that September, Farrell would be assigned to Montreal's American Hockey League (AHL) affiliate, the Laval Rocket, to start the 2023–24 season.

[15] He also tallied eight points (5G, 3A) in six games as part of that year's World Junior A Challenge en route to a third place podium finish for his country.

[22] Farrell began his studies at Harvard University online during his final USHL campaign while the collegiate athletics season had been canceled.