He previously coached in the CFL with several teams and is a two-time Grey Cup winner with the BC Lions and Saskatchewan Roughriders.

That year Montreal lost to Edmonton, in double overtime, in the 93rd Grey Cup game held in Vancouver, BC.

In 2007 the Blue Bombers made it to the 95th Grey Cup, losing to Saskatchewan Roughriders 23–19, without their starting QB who was lost in the previous game with a broken arm.

[7][8] On October 6, 2022, it was announced that McDiarmid had joined the Ottawa Redblacks to serve as a special teams assistant coach.

[9] On March 21, 2022, the Panthers Wrocław in the European League of Football announced that McDiarmid will serve as the special teams coordinator and running backs coach for the 2022 season.