Speaking after the game, Richmond coach Damien Hardwick said the early prognosis was grim for the club's mainstay down back.
"It's probably a suspected ACL at this point," Hardwick said.
"It's incredibly disappointing, but measure of the man you wouldn't know it by his demeanour. He's such an incredible person first and foremost.
"It's going to be disappointing if it is (an ACL). He's an incredible player and you hate to see those players go out of the game.
"We'll cross our fingers and hope for the best, but it's looking dire at this stage."
Playing in his 200th game, Rance went straight to the dressing rooms after hurting his knee, but returned to the bench to see out the match with ice heavily strapped to the injury.
However, despite the club holding grave concerns about the scans he will undertake in the coming days, the Tigers do not believe it will ruin their premiership hopes.
"Of course, it's a challenge," Hardwick said.
"He's obviously a champion of the game and he's one of the best full-backs I've ever seen
but these things can be overcome.
"It's disappointing to lose such a fantastic player, but it also provides an opportunity for someone else to get some games under their belt. We'll get to find a player.
"Are they going to be to Alex Rance's standard? They're certainly not going to be straightaway. It's very hard to replace Alex Rance. But it will give someone an opportunity."
https://www.afl.com.au/news/2019-03-21/tigers-superstar-leaves-field-with-knee-injury