Bombers Head Coach Mike O'Shea confirmed the news that most expected.
Nichols appeared to injure his left leg during the Bombers loss against BC on Saturday.
With Saturday's loss, the Bombers have now lost three of their last four, and if they don't win Friday, they may not host a playoff game for another year.
Beat Calgary - Host Semifinal.
Lose to Calgary and Edmonton beats Saskatchewan - Edmonton would host Semifinal.