TRENT Cotchin's looming exit will give Richmond added motivation to finish off the season well, interim Tigers coach Andrew McQualter says.

Cotchin will miss Sunday's clash with St Kilda at Marvel Stadium due to calf soreness but is hoping to be back for Richmond's final two games.

The Tigers remain an outside chance of playing finals but will need to secure wins from their remaining three games.

Cotchin is set to return for next week's game against North Melbourne and play against Port Adelaide in round 24.

"Trent’s been a warrior for our club for a long period of time," McQualter said on Saturday.

"Now we know for certain that he’s finishing up at the end of this season. 

"We’ll reflect on that, so we’ll try to play in a way that does justice for Trent."

Richmond was inspired by Cotchin the last time they faced the Saints, winning a thriller in round 14 in the triple premiership captain's 300th game.

But St Kilda also has serious motivation to perform, currently sitting seventh (11-9) and needing to win at least two of the final three matches to be assured of playing finals for just the second time since 2011.

Forward Tim Membrey returns for his first outing since round nine and will combine with star Max King.

"We've got to earn the right (to play finals)," Saints coach Ross Lyon said.

"We've been up and down a bit, we're trying to play our best footy and Tim Membrey will help that.

"He's a power forward and him and Max kicked (86) goals between them last year and we basically haven't had them (in the same side this season).

"Our young forward line has done their best, but maybe it's the right time for King and Membrey to get to work."