They were the 'Super Subs' on Thursday night.

A day after the AFL introduced the allowance of a medical substitute for all games during season 2021, both Richmond and Carlton were forced to use their additional 23rd man in the midst of a brutal season-opener at the MCG.

Oscar McDonald replaced the injured Jack Silvagni at half-time for the Blues, kicking a goal with his first touch for his new side and finishing with two majors for the night in a standout performance in attack.

Tigers youngster Jack Ross then racked up eight disposals in just over a quarter, providing additional run through the midfield having come on for the stricken Nick Vlastuin as the reigning premiers eased to a 25-point victory.

According to Damien Hardwick, there's "no doubt" both substitutes made a significant difference to the contest. But for Richmond's triple-premiership coach, that shouldn't be an excuse to suggest the rule can provide an unfair advantage.

"Jack Ross was terrific," Hardwick said.

"There's no doubt, you could tell the difference between both players. Jack was very good when he came on and he made a difference straightaway. He found the ball well. Oscar kicked a couple of goals, one long goal that was a beauty.

"Once again, there will always be drawbacks for everything. But I think the positives outweigh those."

Vlastuin will undergo scans after copping a knock to the knee, which forced him out of the game during the third quarter. However, Richmond remains hopeful the defender will recover during a 10-day break ahead of the club's round two clash with Hawthorn.

Premiership captain Trent Cotchin is a certainty to face the Hawks, having missed Thursday night's encounter with gastro, while veteran defender Bachar Houli is an outside chance to feature following a calf injury.

"Nick got that knee complaint," Hardwick said.

"We're not exactly sure what that is … but he'll have scans tomorrow. But from our point of view, it was fine. Once again, you look at the game, there are 75 rotations … it was tough. It is going to be difficult.

"People jump up and down about it, but the more players that play is a positive. You've got limited rotations, so one more player on the ground isn't going to make a big difference for me.

"I'm all for the growth of the game. For me, if it's going to make it better, then let's do it. I can't see the downside to it. Once again, the health and safety of players is paramount.

"Realistically, if you've got fresh players there, you shouldn't lose a game with an injured player when you've got a fresh one that can come on and play. I think it's a positive and I'll always look at it from a positive point of view."