Young and emerging Collingwood ruck Oscar Steene has likely had his season ended after suffering a suspected ACL injury during Friday night's six-point loss to Sydney.
Playing in his eighth game of the season and his career, the 22-year-old had been battling hard against star Sydney ruck Brodie Grundy when he went down injured during a contest in the third quarter.
McRae said the injury changed the momentum in the game.
"It's not looking good, unfortunately," McRae said post-match.
"The early diagnosis is a full reconstruction. Again will have to get scans to confirm all of that. That's sad. To see what he was capable of against Brodie, who is clearly one of the better ruckmen in the competition, he was really holding his own, and we had a lot of ascendancy from that.
"I think we might have been around 16 points up or close to it at the time (of injury), and then the game changes. We just had to have the next man up. We had Dan McStay, Jack Buller, Nedand Long trying, but not many teams can cope when their number one ruck goes down like that against an opponent like Brodie."
Collingwood started the game in scintillating touch, booting the first five goals before Sydney clawed the game back across the following three terms to win a thriller in the wet.
McRae said his side's injection of youth was a positive sign for the club's direction.
"We had a deliberate plan, and it wasn't overwhelming for our young group," he said. "We had parts of our game that we executed beautifully.
"We did a lot right. We turned up tonight with probably the youngest team we have put on the paddock, probably since I have been involved. I'm not sure about the actual data around that, but we left our number one ruckman out, the captain stayed at home, Patty Lipinski, 150 games, had a lot of experience, and we brought in youth."
