However exciting forward Liam Jurrah could be forced to miss Sunday's MCG clash as the rigours of his first year of AFL football begin to take their toll.
The Demons have a raft of injuries and Bailey admitted Thursday's training session would be critical to a number of player's chances ahead of the Richmond match.
Grimes has missed a week with a back complaint while McLean missed last week's loss to the Sydney Swans with a knee injury.
Bailey said Thursday's session, which would entail some high-pressure, match-style drills, would determine who was fit to play.
"Training tomorrow is going to be important," Bailey said from Junction Oval on Wednesday morning.
"Not just for those two (Grimes and McLean), but we've got a couple of other guys that are in the mix as well."
Bailey said Jurrah would also need to prove his fitness.
"We'll see how LJ goes tomorrow but he's rolled both ankles in the last couple of weeks," he said.
"He's a pretty important player for us at the moment, and he's had a long season with no pre-season."
In brighter news for Melbourne fans, in-form midfielder Colin Sylvia has served a three-match suspension and will vie for a call-up.
Bailey said goalkicker Russell Robertson didn't have a great game in tough conditions in the VFL last week but would be among those considered.
The Demons head into the clash with some confidence, having knocked off the Tigers in round four.
Richmond has endured a turbulent year and has a different coach since that dismal day. However Matthew Richardson did play against the Demons and Bailey has been a keen observer this week to see whether the Tigers veteran can prove his fitness to take the field against Melbourne.
"It'll be an interesting game on the weekend and it'll be interesting whether Matthew Richardson comes up and plays," he said.
"There's still some conjecture on whether he's going to play or not, so if he doesn't play that's good."
Many believe Richardson will return to football with Richmond's VFL affiliate Coburg, but Bailey wasn't so sure when quizzed if he thought the star might play senior football this week.
"You never know, do you?" he said.
