[6] Nicknamed 'Big Mac', McDermott was a Great Britain international forward who played his entire career at club level for Bradford, winning Super League Grand Finals and Challenge Cups with them.

He played amateur rugby league as a junior for Eastmoor RLFC and was a Royal Marine for five years before becoming a professional player.

[7] He played for Bradford Bulls from the interchange bench in the 1999 Super League Grand Final which was lost to St Helens.

[4] McDermott played for the Bradford Bulls at prop in their 2001 Super League Grand Final victory against the Wigan Warriors.

As Super League VI champions, the Bradford Bulls played against 2001 NRL Premiers, the Newcastle Knights in the 2002 World Club Challenge.

He also played for Bradford from the interchange bench in their 2002 Super League Grand Final loss against St Helens.

At the start of 2017, with only the addition of Matt Parcell to the Leeds squad from the previous year, they finished runners up to Castleford in the table.

They then beat Castleford in the 2017 Grand Final at Old Trafford, with long-serving players Rob Burrow and Danny McGuire leaving the club as champions.

In 2015, McDermott was named head coach of the United States national team, combining the job with his role at Leeds.

[40] It was reported on 22 October 2021 that he had taken over as head-coach from James Webster[41] McDermott became assistant coach at the Newcastle Knights in November 2022, ahead of the 2023 NRL season in Australia.