Essendon coach Brad Scott fears unique players could be "bred out of the game", urging new AFL football performance boss Greg Swann to scrap the controversial sub rule.
Scott has been a long-term advocate for getting rid of the sub, moving to five players on the interchange bench instead.
His views come after his twin brother, Geelong coach Chris, and Hawthorn's Sam Mitchell, were on Monday night insistent about axing the sub.
A recent poll of the 18 senior coaches came back with the majority in favour of an extended bench instead of a sub.
Scott "doesn't see the argument" for keeping the sub, believing the interchange cap has stopped teams from being disadvantaged if they lose a player to injury during a game.
But his "greatest concern" is how it impacts the structure and balance of teams.
"It creates all sorts of problems around play load," Scott said on Tuesday.
"With the ruck rule changes, we're very, very quickly breeding the Nic Naitanui (former West Coast star) type of ruckman out of our game, because you can't jump at centre bounces anymore.
"I can't think of the last time you genuinely saw two ruckmen jump at each other over the course of a game; they just come across and bully each other.
"If Nic Naitanui was playing in our game right now, I very much doubt we have the ruck rules that we do.
"Because what he does so well would just be taken away.
"By having a sub, it makes it very hard to play two ruckmen, but by having five on the bench, I suspect more teams would at least look at it."
Scott pointed to former Fremantle giant Aaron Sandilands and ex-North Melbourne champion Brent Harvey as being two completely different players, but both being able to be stars of the AFL.
"I just wouldn't like to see our game breed out certain types," Scott said.
"I have concerns around the rucks at the moment, and the sub and the bench is part of the reason for that."
Swann - the former Brisbane Lions chief executive, who started in his new role at the AFL on Monday - has hinted play could be sped up before the end of the season as he prioritises reducing the length of matches.
The veteran administrator has ruled out reducing the 20-minute playing time for each quarter, but believes the league can tighten up situations where umpires are waiting for players to get to ruck contests and boundary throw-ins.
"We should just do that instantly, I don't know why we wait," Scott said of Swann's suggested plan.
"If the ruckmen can't get there, that's their issue.
"I've been really encouraged by Greg's comments about speeding the game up.
"The game's creeping out, it's getting longer and longer."
