Haye splits from McGuigan, still plans to win world title...

[Primo Carnera]

Mcguigan told Haye that he should retire so Haye left him.

if that is true and the injury is healing as haye says it is then that's bad advice

a fit haye that would last 5 rounds would beat bellew, if his heart is still in it, which it seems to be then why not at least aim for that?

Well that's clearly not true, because he lasted 5 rounds and didn't beat Bellew. and if , as you say , (and I believe) he had the injury before he went in the ring, He should never have entered the ring. To go in the ring with a clear injury when he's earning the money he was , with all the spectators and PPV customers paying is scandalous! he has in effect conned the public.
when the public pay their money and these guys earn the ridiculous money they earn for a meaningless fight, then they should at least be "match fit".
Still , if that doesn't bother you, carry on shelling out your dough for panto match ups.

if Haye was fit from the off then the tactics were shocking and mcguigan deserves the sack

IMO he fought 5 rounds knowing the leg would go having done very little, if any, sparring in the build up

I'm trying to get this straight from your comments. It doesn't seem like you have a problem with the fact that he may have gone into a fight knowing he was injured.
I find this all pretty strange to be honest.
I've always liked and rated Haye, so I'm not a hater. But if a guy goes into a fight where he's earning , let's face it, way more than what the fight is worth, you at least want him to be fit surely?