Damien Hardwick concedes Richmond co-captain Dylan Grimes is unlikely to play again this season unless the Tigers make a deep run into the AFL finals.
Grimes will miss the remaining three home-and-away rounds, starting with Saturday night's crunch game against Port Adelaide because of his latest hamstring setback.
The triple-premiership defender had surgery on Thursday to repair tendon damage in the hope he can return during September.
"He won't play in the regular season, that part's done and dusted," Hardwick told reporters on Thursday.
"(It depends on) how far we go in the finals and it gives him a chance if we make it.
"This (surgery) gives him his best chance to get back this year, we feel."
In the meantime Josh Gibcus and Rhyan Mansell are in the frame to plug the hole in defence.
"We've got some players who can fill the void although we are replacing a pretty valuable player," Hardwick said.
Richmond sit two points behind eighth-placed St Kilda after last week's thrilling win over Brisbane and take on a dangerous Port Adelaide at Adelaide Oval before matches against Hawthorn and Essendon in the run home.
The finals race lingers as a possible distraction but Hardwick doesn't expect any issues keeping his side focused on the immediate task at hand.
"It's pretty easy, that's what we do," he said.
"We stick firmly to what we can control and that's this week's game versus Port Adelaide.
"Our prep is firmly on them and the way they play the game."
