Anthony Joshua v Andy Ruiz Jr: Mike Costello and Steve Bunce on what happens now

Anthony Joshua on his knees after being knocked down by Andy Ruiz Jr
Anthony Joshua was knocked down four times by Andy Ruiz Jr

The dust is only just starting to settle on Andy Ruiz Jr's stunning win over Anthony Joshua in New York.

The Mexican's victory at Madison Square Garden has blown the heavyweight division wide open and left the Joshua camp wondering what went wrong.

BBC Sport boxing correspondent Mike Costello addresses the rumours about Joshua being knocked down in sparring and possible illness hampering his preparations. BBC Radio 5 Live boxing analyst Steve Bunce also reveals what Robert Joshua, Anthony's dad, said to him following his post-fight rant at Eddie Hearn.

And with Hearn already confirming a rematch in November or December, the 5 Live boxing team consider what Joshua needs to change in order to regain his titles - with some additional input from Hearn's father Barry.

Steve Bunce: You can underestimate a fighter without cutting a single corner in training

Was illness or a knockdown in sparring a factor?

There has been speculation that Joshua was knocked down in sparring in the immediate build-up to the fight, denting confidence. There were also rumours Joshua had been suffering from illness, although the 5 Live boxing team doubt they were key factors in his defeat.

Bunce: "We flagged up a nasally feel in Joshua's voice on Monday, clear signs of some sort of cold or maybe being run down, but not enough for us to predict the shock that came."

Costello: "If you look at some of the TV footage, after the second round, he says to Robert McCracken 'why do I feel like this?' If he had a cold, if he had been knocked out badly in sparring, he wouldn't be asking Rob McCracken why he felt like that - he would have known why he felt like that and feeling so rough so early in the fight."

Bunce: "If he was hit on the chin and dropped in sparring it wouldn't be the first time. He admits to being dropped by David Price. The issue could be how close it happened to the fight, but that doesn't instantly equate to him not wanting to fight because he was gun shy. The seriousness of that accusation is was he then checked medically afterwards?

"His team acknowledge that he was tired, that it had been a gruelling schedule. It might sounds like a fantasy life but it's a draining procedure to go through if you haven't done it before. My gut feeling is perhaps the whole five weeks of being in Miami and New York was draining."

Hearn: "Rumours of a panic attack are absolute nonsense; he was ice on legs. Got knocked out in sparring? No he didn't. The build-up, the training camp, the organisation - he's got 22 people in his team and every single whim is catered for. It's a very professional organisation. Absolutely zero excuses."

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What did Robert Joshua shout at Eddie Hearn?

Robert Joshua, Anthony's dad, shouted at Eddie Hearn in the ring immediately after the fight, with Anthony forced to intervene. That sparked speculation Joshua was maybe pushed into fighting when he wasn't fully fit. But Steve Bunce urges caution when trying to assess what happens in the immediate aftermath of a passionate fight.

Bunce: "I had a chat with [Robert] outside the fight hotel [on Sunday afternoon]. I asked him how things were, he said they were fine, and words to the effect of 'we will rebuild, he'll be back'.

"Let's be really careful about how we deal with the rumours. If there was some kind of crisis of confidence in the two hours before the fight - some people have called it a panic attack but these are just expressions being thrown around - but if he wasn't feeling brilliant in the changing room, and that would also tie in to what he said to Rob McCracken after round two, then maybe someone did think about whether the fight should happen or not.

"So perhaps that's what Robert Joshua was talking about, because that would lend a bit of credibility to AJ's words to his dad 'no Dad, it was me'.

"But let's get this clear: we don't know. That could be completely out of context. We've got to remember - what happens in a ring is chaotic. Sometimes we're too busy searching for something sinister to not realise that's just human nature in the extreme when a fight like that ends."

Anthony Joshua and his dad Robert in the ring after his defeat Andy Ruiz Jr
Anthony Joshua and his dad Robert in the ring after his defeat by Andy Ruiz Jr

Did Joshua underestimate Ruiz?

Ruiz wasn't even supposed to be in this fight. He took the bout at six weeks' notice and was a huge outsider with the bookmakers. Bunce and Costello both feel that might have affected Joshua's approach.

Costello: "After a shock of this magnitude you wonder, how did you not see this coming? We admit to being impressed by the general make-up of Ruiz but we didn't think he would win the way he did. I wonder if somewhere, buried in Joshua's subconscious, because this was a substitute, maybe there was a feeling it wasn't quite a tough as test as Jarrell Miller would have been."

Bunce: "You can underestimate a fighter without cutting a single corner in training. Somewhere in your mind you are doing it differently."

Hearn: "The brain is a funny thing. You can tell yourself over and over again to not underestimate your opponent and maybe he did. The only person who knows that is Anthony Joshua himself."

What does Joshua need to change?

Eddie Hearn has confirmed that Joshua will meet Ruiz again in a rematch late this year. But what does Joshua need to do to avoid another upset? Lennox Lewis has suggested a change of trainer, but Bunce is not so sure.

Bunce: "I can't see where Robert McCracken put a foot wrong. He put in some great sparring partners, a great training camp and some of the stuff he was saying between rounds was brilliant. I respect Lennox but I'm not sure dropping Rob is any type of solution.

"We need to find out now what AJ's made of, how much desire is there? Can he go somewhere and find that 'eye of the tiger', and what would he need to change in his life to get like that?

"Eddie Hearn hinted there could be less press commitments down the line. I would argue that it's commercial commitments that need to change. What should be in the diary is who is coming in to spar not the latest catwalk."

Hearn: "I think he will look at the way he fought, his tactics for the fight. He had a lot of physical advantages that he didn't utilise. I think he steamed in very raw when he got knocked down - he went for the kill. There's nothing wrong with that, but he was very reckless when he went in and he caught a punch in the third to the temple which gave him concussion and I don't think he was in the fight from then on.

"Joshua and Robert McCracken are very sensible guys. They will watch it back, mark where they went wrong, learn, improve and reclaim. Easy for me to say; tough for him to do."