Easy to say from the outside, but with all due respect, you have not been following his recovery closely, nor do you have any insider knowledge to make that claim.30+ years old and a 3rd ACL is simply not a good combination to take even the slightest chance in this situation.
Going extra conservative and preparing Sam for next year would be the wisest cause of action. Think how much extra strength and conditioning work he can get through. Carlton aren't contending for a premiership this season but they could in 2025.
Look, it'll probably be fine if he plays but the risk to reward profile just isn't there for most clubs. Carlton are mad enough that I do think they'll seriously consider playing him though, that's the scary thing.
The thing with ACLs is that he could do it anytime. During training, during the off-season, round 1 next year. Say we play him as sub, does the benefit of his presence and leadership outweigh that risk?