As Anthony Joshua was led back to his dressing room at Madison Square Garden after defeat by Andy Ruiz Jr, boxing fans around the world were left reeling.

The Mexican underdog’s seventh-round TKO win over the heavyweight champion was arguably the greatest upset since Mike Tyson was dethroned by Buster Douglas in Tokyo in February 1990.

The stunning manner of Joshua’s first career defeat – a bout in which he was knocked down four times – prompted fans and pundits to scrutinise revered trainer Rob McCracken.

Rob McCracken is under pressure to come up with the perfect game plan when Anthony Joshua fights Andy Ruiz Jr in a rematch at the Diriyah Arena in Saudi Arabia on December 7

Former heavyweight king Lennox Lewis led the inquest, writing: ‘I say you can’t go to university with your third grade teacher. They won’t have the answers you need at that level. You need a professor by then.

‘McCracken is A1, without question, but maybe not the fit for the style AJ needs to fight. I switched to Manny Steward, who understood how to leverage all of my physical attributes and skills, and showed me everything I needed to know for success.

‘He (McCracken) may not be right for the type of style that AJ needs to master. Aside from that, AJ was not prepared for anything Ruiz brought to the table.’

Lennox Lewis (right) urged Anthony Joshua to find a new coach after defeat by Ruiz Jr

ROB MCCRACKEN FACTFILE

Age: 51

Born: Bordesley, Birmingham

Boxing career: 35 fights, 33 wins, 2 losses

British light middleweight champion

Commonwealth middleweight champion

Current role: Team GB Boxing performance director + Anthony Joshua’s head coach

Years active as a coach: 2001-present

While Lewis has challenged his ability to improve elite fighters, McCracken, 51, is undeniably an exceptional coach in the amateur game.

He was awarded an MBE after Great Britain topped the boxing medals table at the London 2012 Olympics with three golds, one silver and one bronze.

Team GB Boxing won an impressive 48 medals in 16 major international tournaments after his appointment as performance director in November 2009, including Joshua’s gold in 2012.

In the opinion of world-class programme coach Paul Walmsley, McCracken’s ‘firm but fair’ approach has been the catalyst for national success, which extended to a further two medals at Rio 2016.

McCracken gives Joshua advice during a training session at the English Institute of Sport

McCracken also had a distinguished career inside the ring, turning professional in 1991 and winning the British light middleweight title in 1994, before stepping up to middleweight and winning the Commonwealth title in 1995.

His first defeat came at the highest level, losing by 11th-round stoppage to WBC champion Keith Holmes in April 2000. Defeat by Howard Eastman a year later convinced the Birmingham-born fighter to retire with a record of 33 wins and two losses.

He immediately embarked on a coaching career, and over 14 years transformed apprehensive amateur Carl Froch into a four-time super middleweight world champion, recording wins over Jermain Taylor, Lucian Bute and Mikkel Kessler along the way.

He guided The Cobra through 12 consecutive world title bouts and formed an unbreakable bond with his fighter.

In Froch’s autobiography, he reveals McCracken’s mother had passed away on the morning of his battle with Jean Pascal, but the trainer kept it a secret so as not to unsettle Froch on the biggest night of his career.

McCracken leads a public workout with Carl Froch ahead of his rematch with Mikkel Kessler

McCracken showed the sacrifices he is willing to make for his fighters when Froch defeated Jean Pascal in December 2008 – McCracken’s mother had died and he kept it from Froch

In the background, McCracken was overseeing Joshua’s development at the English Institute of Sport in Sheffield. 10 years on, he must devise a plan to regain AJ’s belts from Ruiz Jr on December 7.

The trainer acknowledged his man ‘got greedy’ after flooring Ruiz Jr in New York, throwing caution to the wind against a man who was not prepared to give in.

It would have been unrealistic to expect McCracken to inspire a mid-fight turnaround after Joshua got caught with a fierce left hook to the temple in round three, just seconds after Ruiz Jr rose from the canvas.

McCracken’s pleas to ‘jab’ and ‘beat him with reach’ thereafter were astute and simultaneously gave an indication of AJ’s perilous position.

There were some extenuating circumstances in the first fight. McCracken was right to point out that Joshua had prepared to face Jarrell Miller, the Brooklyn brawler who was banned after failing a drugs test less than 10 weeks before the first bell.

Ruiz Jr (right) is sent to his corner after knocking Joshua down for a second time in round three

Joshua had prepared to come up against Jarrell ‘Big Baby’ Miller at Madison Square Garden

But this does not absolve the trainer. In allowing Ruiz Jr to have pictures taken with the belts at the pre-fight press conference, Joshua showed a level of complacency reminiscent of Froch in 2013, who admitted he ‘cut corners’ in preparation for his bout with George Groves.

Finding a way to cope with Ruiz Jr’s hand speed will be vital, but McCracken must ensure Joshua is mentally prepared for this rematch.

McCracken is a former British and Commonwealth boxing champion

The coach did little to endear himself to the wider public in September when he confessed to knowing AJ was concussed after round three.

It was a ‘shocking admission’ according to brain injury charity Headway, who reminded McCracken of his ‘duty of care’ to fighters.

And it seemed a little irresponsible that a bleary-eyed Joshua was sent back into the firing line after asking his cornerman ‘why am I feeling like this?’ at the end of round six. Referee Michael Griffin stopped the bout less than two minutes later.

However, McCracken’s clarifying statement resonated with those who have set foot in the ring.

He referred to fights where ‘boxers have recovered from a difficult round to win’, with Froch’s unlikely revival in his first duel with Groves proving a case in point.

He explained: ‘I am not a doctor and it may be that concussed is not the right term to have used, but the health of all the boxers I work with is of paramount importance to me and I have always used my judgement and experience to do what is right for them.’

McCracken revealed in September that he knew Joshua was concussed after the third round

Joshua asked his trainer ‘why am I feeling like this?’ just moments before getting stopped

Since McCracken’s appointment as Joshua’s head coach in December 2016, he has recorded some momentous victories. Most notably, the compelling Wembley win over Wladimir Klitchko in April 2017.

Against Joseph Parker, he displayed a more pragmatic jab-and-grab style which could prove effective against Ruiz Jr.

Alternatively, the 30-year-old could revert to the more expansive style endorsed by former coach Tony Sims; it was a method which worked against Dillian Whyte in 2015.

An emphatic win would reignite the interest of rivals Tyson Fury and Deontay Wilder, but after such a deflating knockout at Madison Square Garden, it’s most likely a leaner Joshua will take a tentative approach in Saudi Arabia.

It is to be expected that McCracken will advise his man to fight at range and avoid the American’s swinging hooks at all costs.

McCracken holds Joshua’s IBF belt after a win over Eric Molina in their first fight together

As revealed by Sportsmail last week, Angel Fernandez – who coaches Isaac Chamberlain – and Joby Clayton have joined Joshua’s camp as pad men, giving McCracken a more overarching role.

Joshua has used specialist pad men in the past, but the news does little to dispel rumours that his faith in his trainer has diminished.

McCracken is wise to mention that nobody questions the coach when the fighter is winning, but boxing can be a fickle sport. His reputation, as well as four belts, will be on the line in Diriyah next month.