The Bulgarian midfielder was diagnosed with acute leukaemia on Friday and will begin to undergo treatment on the illness immediately.
Since the news broke, Petrov has been inundated with messages of support from fellow players and McLeish now wants the 32-year-old's teammates to give their skipper a tribute on the pitch.
"The players will be gutted but hopefully galvanised to win this game for their captain tomorrow," McLeish said.
"Stiliyan, I'm sure he will be rooting for the lads tomorrow and sending some of the vibes for these boys to be inspirational for this game against Chelsea."
"I know that some of the players are already texting each other and saying that kind of thing (this will be for Stan) to each other and I'm sure they'll be no doubt about that at all."