Grimes added that Martin seemed to be happier after the 2017 Brownlow Medallist had revealed his struggles with anxiety and depression through last season.

Martin did not quite reach the heights of his all-conquering 2017 season and played hurt in Richmond's preliminary final loss.

But Grimes is talking up what the star midfielder is capable of this season, which starts on Thursday against Carlton at the MCG.

"In my opinion, he's had his best pre-season," Grimes said.

"He's fitter than he was this time last year and stronger as well.

"I'm pretty confident he'll have a terrific year."

Grimes praised Martin, normally a private person, for going public with his mental health challenges in a rare media interview.

"It's incredibly courageous of him to stand up, not only in front of the media, but also his teammates and voice the struggles he has," Grimes said.

"I'm sure he's a stronger person this year because of it.

"He seems to be in the best place of his whole career."

It remains unclear whether star recruit Tom Lynch will be ready for the Carlton game as he returns from a knee injury, but Grimes is excited by what he has seen of the ruck-forward.

"He's pretty close (to playing) - I've only seen what he's done on the track and it's pretty spectacular," the key defender said.

"Tom's obviously an amazing athlete.

"He's six foot seven, 105kg and runs like the wind and moves like no one else we have.

"To have someone like that on the team would be a huge asset."

Richmond will start favourites on Thursday night, but Grimes says the Blues this year are a much tougher proposition.

"The whole world has seen how much Carlton have improved," he said.

"They've played some good footy over the (pre-season).

"I'm sure it's going to be a battle, as round one always is."

Australian Associated Press