The former Notts County man is struggling with the injury yet could get through the game. The club and player, however, have opted to rest the knee with the hectic Christmas schedule coming up.
The absence of Cas has forced Groves to bring Alan Pouton to the fold, ahead of plan.
The man who Groves dubbed the 'hub' of the team has yet to complete a reserve game on his comeback from a long term knee injury, yet is still likely to be in the 16 tomorrow.
"Pouts is on the bus with us today and we'll go from there," Groves told the Grimsby Telegraph.
"We've said about the importance of having someone like Pouts around the squad.
"He plays in an important position for us and he's an impact player - anyone would miss someone like him.
"Alan has made decent progress and has got good time under his belt. He's getting closer and closer.
"Alan had eight weeks out where he couldn't do a great deal. He's getting to the stage now where he's done his pre-season work and he's getting in and around it.
"We'll need another midfielder on the bench and need to add to the squad."