Alex Rance's knee injury has sent a massive scare through Richmond, who survived another fright from Carlton to open the AFL season with a 33-point win.
Rance was pessimistic about his prognosis immediately after Thursday night's 14.13 (97) to 9.10 (64) win at the MCG.
"I will find out the severity - the initial signs don't look too good," Rance told Channel Seven.
Rance was in agony when he left the field in the third quarter of his 200th match.
The star defender was in good spirits when he emerged from the changerooms in the last quarter and limped to the bench, but it looks like Rance is a long-term casualty.
Leading by only two goals at three-quarter time, the Tigers went to their celebrated extra gear to secure the win.
The Tigers ended the game as they started, out-scoring the Blues by four goals to one in the last term after their five-goal blitz in the first.
But there was plenty to like about the young Blues, who pushed the premiership fancies hard in front of 85,016 fans before their challenge ran out of steam.
In his first game since last year's knee surgery, star Tigers recruit Tom Lynch kicked three goals.
Captain Trent Cotchin was best afield with 31 possessions, while new Blues co-captain Patrick Cripps also impressed and teammate Harry McKay was dangerous all night in attack.
The start of the game was a reversal of Carlton's storming five goals to nil sequence a year ago.
This time, the Tigers piled on five goals to a behind in the first term and another goal early in the second for a game-high lead of 40 points.
Lynch had a dream start to his time at Richmond, marking and goalling two minutes into the match and adding another later in the first term.
The match looked as good as over, even when former Collingwood player Alex Fasolo finally kicked the Blues' first goal seven minutes into the second term.
But with Cripps growing in influence at the stoppages and McKay a persistent threat, the Blues steadied.
They kicked four goals to two in the second term and only trailed by 22 points at halftime.
Two goals to the Tigers in the third term took the margin back out to 26, but the young Blues had a sniff and they counter-attacked again.
Former captain Marc Murphy snapped a goal in his 250th match and Nic Newman added another.
Then Rance landed awkwardly in a marking contest and was in agony as two trainers helped him from the ground.
Symbolically, Carlton managed to stop Tigers star Dustin Martin twice with crunching tackles, giving him no chance for his signature "don't argue" fend-off.