Didak is still battling to recover from a hamstring injury while Medhurst missed most of the second half of last week's win over North Melbourne with an injured ankle.
"Dids will miss. He definitely won't play. Medders would be a pretty good chance. The 10 days helps him a lot," skipper Nick Maxwell said on Thursday.
He said he had confidence that Collingwood could cover whatever injury problems were thrown at it.
"We're pretty comfortable at the moment with the depth we've got. We showed last week when (Anthony) Corrie and (Sharrod) Wellingham came in at the last minute that there are a lot of VFL guys knocking on the door," Maxwell said.
Maxwell said Shaw had progressed well from a hamstring strain and there was still plenty of time until Monday night's clash.
"He's a really good chance. We've still got two training sessions to go, so to be honest we haven't really talked about a team or what we're doing. We'll go through that tomorrow and he'll train tomorrow. I'd expect him to [play]," he said.
Maxwell said he was happy to be playing on Monday night and said it would not disrupt the team's usual weekend.
"A couple of our guys were a bit sore from the weekend and it gives them a chance to heal a bit better," he said.
"There is no real difference for us. It's probably more different for the supporters who wouldn't be used to something like this."
