The three-time premiership player had 12 possessions in Richmond's stellar comeback victory over the Western Bulldogs.

But after reporting concussion symptoms on Saturday, Grimes has been ruled out of this Friday night's blockbuster with Geelong at the MCG.

"The doctor naturally had to look a little bit deeper into it because there was no obvious incident from the game Friday night, but his symptoms were consistent with some kind of concussion episode," said Tigers physical performance manager Peter Burge.

"We are being absolutely cautious with this. It is very important, the player's welfare, so Dylan will miss the game this week under the concussion protocol."

Cotchin, who has endured a torrid run with soft-issue injuries, hurt his hamstring late in the contest against the Bulldogs.

The Tigers will take no chances with the 31-year-old given his injury history.

"(Cotchin) is going to miss a couple of weeks and fall into the medium-term bracket," Burge said.

"(He will) go through our hamstring rehab protocol and we will make sure he is absolutely right to return."

The better news for Richmond is superstar Dustin Martin (concussion) and ace defender Nick Vlastuin just need to get through training on Wednesday to prove their fitness to face the Cats.

The Tigers moved to a 4-3 record with the 22-point victory over the Bulldogs ahead of their first match against Geelong since a barnstorming second-half in last year's decider ensured they claimed their third premiership in four years.

Australian Associated Press