RICHMOND will be without star defender Dylan Grimes and skipper Trent Cotchin for its Grand Final rematch against Geelong on Friday night.

Grimes developed concussion symptoms on Saturday following the club's big win over the Western Bulldogs, but medicos were unable to pinpoint a particular incident which could have been the cause.

Hamstrung Cotchin has been listed as "medium term" by the club, indicating he will be sidelined for around 3-4 weeks after suffering yet another soft tissue injury.

The 31-year-old left the field in the dying minutes of Friday night's victory, and has a recent history of hamstring woes.

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

"He now falls into the AFL concussion protocol and will miss this week’s game. 

"It is something we have dealt with before with Trent over time, so he is going to miss a couple of weeks and fall into the medium-term bracket."

In better news for the Tigers, both Nick Vlastuin (knee) and superstar Dustin Martin (concussion) are "probable" for this weekend's big clash against the Cats.

Ivan Soldo has had further surgery on his reconstructed knee, needing work on his medial ligament.

The club is not expecting the latest setback to push out his return timeframe too much, having initially torn his ACL late last season.

Integral runners Kane Lambert and Dion Prestia (both calf injuries) are still listed as being at least three weeks away.