Carlton fears the worst for defender Ciaran Byrne after the Irishman was taken from the ground on a stretcher in Saturday night's clash against Collingwood with a serious knee injury.
Byrne, who has established himself as a regular in the Blues' back six this season, will have scans but is likely to be sidelined for the next 12 months if he has suffered an anterior cruciate ligament injury.
The 21-year-old punched the ground after landing awkwardly in a marking contest and was visibly upset as club doctors assessed his right knee and then took him from the MCG late in Saturday night's 12-point loss.
"I'm pretty worried about that," coach Brendon Bolton said when asked if an ACL injury was likely.
"I think all our coaching team, myself and the players as well, we spend a lot of hours together and when you invest so much time and effort together it does hurt emotionally.
"But we'll support him and that's all you can do. That's the risk when you run out and play AFL footy."
Byrne's injury compounded a bad night for the Blues, who kicked just 6.9 – including 1.5 across the second and third quarters – in a dour clash against their arch rivals.
The shining light was the unveiling of third-generation Blue Jack Silvagni, who finished with 15 possessions and a team-high seven score involvements in a neat debut.
"It's step one in hopefully a really long career," Bolton said.
"I think in terms of third generation at our club, it's something to be excited about.
"I hope our members are excited about it, but we still need to keep it in perspective.
"His work-rate was solid, he was running hard out the back, leading up at the ball-carrier. It was more about his running patterns as a forward."
Bolton would not commit to keeping Silvagni in the team for an extended run but said "form always dictates whether or not you are in the side".
"We're pleased with his first game … first up, he did some OK things," the coach said.
Silvagni said he enjoyed his first senior game but now needed to work on his fitness after fading in the final term.
"It was a life-long dream fulfilled tonight," the 18-year-old told broadcaster Channel Seven.
"But ultimately from a team perspective it's pretty disappointing because our skills let us down and we couldn't execute when we needed to, and that resulted in a loss for the club.
"It was really good and really enjoyable … I've just got to work on my fitness now because I was blowing a lot in that last quarter."
Silvagni took two contested marks, including an impressive grab opposed to Jeremy Howe, and he was a solid contributor with four inside 50s.
He chose to pass off a goal-scoring opportunity in the last 10 minutes after marking 15m out on an angle, finishing goalless but with plenty of admirers.