After waking from a five-hour operation to reconstruct his right shoulder, David Haye admitted it would take a ‘medical miracle’ for him to fight again.

Twenty-four hours earlier he had flown to Munich where Professor Andreas Imhoff, a specialist in trauma surgery, had re-attached the ruptured joint.

As a result, Haye’s £10million fight against Tyson Fury was shelved for a second time and he was advised to retire.

But for every doctor who recommended he hang up his gloves, another insisted he could continue a career that had seen him unify the cruiserweight division and win a portion of the world heavyweight championship.

And so began a 26-month journey that will conclude with Haye, now 35, climbing through the ropes on Saturday night to face the waiting Mark de Mori.

To aid Haye’s recovery further, he was introduced to Aidan Goggins, a nutritional medicine consultant who had, along with Glen Matten, developed the Sirtfood Diet at the exclusive west London gym KX.

The diet is based around a group of foods said to stimulate the genes that influence the body’s ability to burn fat and has become popular with a string of celebrities.

But with Haye, the nutritional mandate was rather different.

‘What we’re doing with David in terms of nutritional medicine is one of the most advanced nutritional approaches for an athlete,’ says Goggins.

‘We do a lot of blood tests and measurements. We measure his nutrient levels, his muscle recovery markers, immune function, inflammation levels and muscle breakdown levels.

‘We would be testing David every week or every couple of weeks at the beginning and then refining and retuning.

‘In the past, he would have been eating the food; the protein, the carbohydrates, ticking those boxes. We went much more in-depth and looked at it from a cellular level.’

As a result of surgery and subsequent lay-off, Haye’s initial test results laid bare the challenge at hand.

‘When David was first doing his training, his immune system was stressed and depleted and his muscle breakdown was through the roof,’ says Goggins.

‘David is a huge hitter and the force he hits with tears his muscles so his breakdown levels were up to 100 times higher than the normal person.

‘What we did is adapt his nutrition to suit that.

‘He follows a vegan-style diet which some people would argue is downfall for a heavyweight boxer but the sirtfoods have properties to enhance muscle function and improve muscle adaption so by incorporating those he saw a greater response from his training and a better recovery which allowed him to gain muscle mass.’

Haye would eat five meals a day, each prepared by a personal chef service, around his training sessions and drink two juices packed with sirtfoods including kale, rocket and parsley.

Much to his chagrin, Haye, a renowned heavy sleeper, was woken by an alarm around the clock in order to eat and is expected to enter the ring up to a stone heavier than when he fought Dereck Chisora in the summer of 2012.

‘David was always a light heavyweight; he was fast so he wanted to keep his speed but be heavier so he can punch harder,’ explains Goggins.

‘I’ve never met an athlete who is more open to driving the nutrition the right way. He wants everything to be perfect, whether we’re talking about markers of muscle recovery or even his cholesterol levels.

‘Even though David’s older, I strongly believe he’s in a much better position and not just in the short-term, he’s in a position to take it on for the next few years.

‘He hasn’t rushed; he’s made sure it’s 100 per cent right and I really think he’s going to reap the rewards.’