“It sounds stupid, but it was as if the stadium went quiet at that exact moment,” recalls former Manchester United defender David May.

“All you could hear was the snap of his leg — as if two shin pads had collided — then the scream.”

He is thinking back to April 8, 1996, the day Coventry City defender David Busst suffered a horrific leg-break at Old Trafford. For many, it remains the worst football injury captured on film.

With four games to go in the Premier League season, Manchester United were six points clear of Newcastle United having played a game more.

Coventry were a point adrift of safety, but they made a start which roused the few thousand away fans, winning a corner after just 86 seconds.

Ally Pickering’s delivery was met by Noel Whelan at the front post, but his header was palmed into the air by the diving Peter Schmeichel.

Busst raced “full blast” towards a rebound which was, at best, 40-60 against him to win.

He was 10 yards outside the back post but accelerated so powerfully that he got to the ball ahead of the two United players, Denis Irwin and Brian McClair, who had thrown their legs at the bouncing ball.

The collision meant the ball only trickled towards goal.

“Instinctively, I thought, ‘He should have scored there’,” says May.

“But then I saw his leg and, oh my God, it was horrible. You could see the pain David was in. I turned away. Just thinking about it sends shivers down my spine.”

Schmeichel was on the ground with the ball safely in his hands but, as he had been making the save, he seemed to witness Busst “sit on his own leg”.

When the Danish goalkeeper looked up, he was met with a sight that would ingrain itself into his brain forever.

Busst had suffered compound fractures to both his tibia and fibula, leaving his right leg hinged at a sickening angle.

“We had five set-piece drills with Ron Atkinson and Gordon Strachan back then and the number they called up was the one that we flick on at the near post and I come in at the back post. It went perfectly until I got challenged,” Busst, who now works for Coventry’s Sky Blues In The Community charity, tells The Athletic.

“I just froze. I had the feeling of knowing something wasn’t in the right place. I thought, ‘Don’t move and the pain will go away, but the pain didn’t go away’. I was scared to move as Dion Dublin had a sheer look of horror on his face.

“Irwin had been coming off the post towards me and caught me above the ankle, but McClair was coming from behind and his foot caught me higher up the shin bone. All three of us were going to win or block the ball, so I don’t blame anyone.

“If you’ve got two opposing forces hitting at that exact same split second, there is only one thing that can happen. It will probably never happen again.”

Manchester United and Coventry face each other in Sunday’s FA Cup semi-final in a fixture that has not been seen in the Premier League since 2001, but it will always be synonymous with the nine-minute stoppage that brought an end to Busst’s career.

“I knew something was really bad with the noise he made, but when I saw Bussty’s hand in the air that was it for me,” says Paul Williams, a Coventry team-mate who had travelled with close friend Busst to meet the team bus that morning.

“Everyone was in their own world when he was down. I don’t think two people spoke to each other on our team.

“I can’t remember one pass I made that day. I wouldn’t even be able to confirm the score to you.”

It ended 1-0 to United, with Eric Cantona scoring the only goal of the game two minutes after half-time.

The details remain a blur for those who shared the pitch that day, including Manchester United midfielder Lee Sharpe, who heard the “crack” from just outside the box.

“It was horrible playing on,” says Sharpe. “No one wanted to go near anybody. It was a weird atmosphere as I think everyone was in shock.

“I remember Pete (Schmeichel) throwing a bucket of water at the blood on the pitch and seeing it splash up red.”

In 1996, the rudimentary setup at football grounds meant both club doctors had to sit in the directors’ box and the paramedics had to stay in the tunnel at the Stretford End so were not allowed on the pitch to give treatment.

It was such an unprecedented incident that United’s players called for their physio, David Fevre, to help.

“Our lads called us on and said, ‘Dave, you need to sort this out’,” says Fevre.

“When I got there David was screaming in pain, so my first thought was, ‘I need two sensible players who can help me out here’. Dion Dublin and ‘Choccy’ (McClair) were talking to him to take the stress out of it for me and create a physical screen so he couldn’t see down.”

Busst’s bone had penetrated through the skin and created a pool of blood in the six-yard box by the time Fevre arrived.

His priority was to stop the bleeding and prevent Busst losing consciousness or any further complications arising. He tried to ensure any grass and dirt was washed away by squirting saline over the open wounds and then dressing them to absorb the blood.

Only then could he deal with the fracture itself.

“His leg was virtually at 90 degrees,” says Fevre.

“Because of the angle, I checked the distal pulses in the foot. If you lose that, you lose the blood supply to the leg and then I would have had an even bigger problem to deal with.

“I made the decision to keep the limb in that position as I didn’t want to lose those pulses. I held the top and bottom end of the fracture as we got him on the stretcher and I maintained that stability while we took him around the pitch into the tunnel where the paramedics could give him oxygen.”

Only the St John’s Ambulance service were allowed on in those days, meaning Fevre had to lead a complex response without much support.

He is one of the faculty tutors at the Football Association and Busst’s injury is one that comes up often.

“I don’t want to sound blase, but having worked in rugby league for 10 years, I got used to injuries like that,” says Fevre. “It hardens you up to deal with it.

“I just went back to my seat and got my mind switched on to covering the rest of the game as something else could happen in the next minute.”

There was such a mess left that referee Dermot Gallagher had to allow the groundsman to come on with a bucket of water and sand.

Gallagher still cannot allow his mind to linger on it 27 years later.

“It took me nigh on two years to go back to Old Trafford again,” he tells The Athletic.

“It was the worst day of my football life and haunts me to this day. I avoid talking about it like the plague.”

Busst was put to sleep as the doctors reset his leg and put it into a back slab, but that was only the beginning of his recovery during an initial six-week stay in hospital.

“I can remember the journey because the speed bumps outside Old Trafford were so massive it felt like I was breaking it over and over again,” Busst says.

“Most people thought it was a road traffic accident until they saw the football kit.

“When Big Ron came to see me, the first thing he said was, ‘Bussty, you should have scored!’. You don’t want someone being morbid as you want people to take the pressure off. No one was better at that.”

Busst needed light relief as he underwent 10 operations in the first 12 days in an attempt to clean out and sterilise areas where he had picked up tissue infections, including MRSA.

He also had a hematoma on the outside of his leg, which had caused so much inflammation that they had to cut it down to release the pressure that felt like one huge dead leg.

Infection then got to his tendons, which also had to be cut away, leaving only the one that connected his big toe.

Busst had a six-inch pin inserted in his leg to help connect the bones and wore an external fixator bolted onto either end of his shin in the hope the bones would calcify and connect in the middle.

He encountered more problems as the infection was trailing down the outside of the pin. That had to be removed via another operation three months later. Busst even required surgery to repair a hole on his left Achilles that had been created by overcompensating when limping.

“One of the big problems I had was there was no blood supply to where the break was. There was a real danger that it would have to be amputated from the knee down,” Busst says.

“They moved the skin off the calf muscle to cover the hole where the bone had come out. They then took a skin graft off my backside to go on the back of my calf, which is why it looks like it does now.

“One of the best operations I had two years later was repairing that so I could pull up my toe. That’s what stopped me playing, I was left with a drop foot. You can’t chip the ball. It took me three years to kick the ball again.”

Busst used to cut out the ends of his shoes so he could have a bit of normality, but he knew after three months he would never play again due to the variety of significant injuries.

“All he wanted to know that first night was if he would play again, but they couldn’t give him an answer. It was horrible,” says Williams, who now plays alongside Busst in an over-35s league.

“On my days off I’d take him up to Manchester for his treatment. I’d put the front seat of my car down and he’d sit in the back with his leg up and all the metal sticking out of it.

“He had come to professional football late and that’s all he wanted to be. To have that taken away from him was devastating, but he’s more resilient than I’d ever be.

“He was quick, honest and committed. That’s what he brought to the game that day and it’s what ultimately ended his career.”

Old Trafford was already significant to Busst in how he had come into professional football. He was a latecomer, having been with non-League club Moor Green in Birmingham until he was 24.

One of his trial games at Coventry had been at Old Trafford in 1991, but five years later, aged 28, he had 50 Premier League games under his belt.

Williams reckons he would have had years more to come, which begs the question: does he ever regret flying into the challenge as committed as he did that day in 1996?

“It’s just something I didn’t even think about,” says Busst. “I was an honest player, I wasn’t the most talented but I stuck my head and foot in where it hurt.

“You’re not looking around thinking who is potentially going to hurt me, you’re just going full-blast to the ball. I was always brought up to attack the ball. If I had thought about those things, I’d have been injured years ago.

“I can’t change anything, but I can see what good I can take from it. Opportunities opened up for me after that. You’re better being famous for something than not.”

David Busst never played professionally again but does play veterans’ football (Getty Images)

Busst has had calls with players and families who have suffered traumatic injuries and, now 57, also plays for Leamington Seniors.

“He still steals into tackles now on a Sunday,” says Williams.

“I remember playing a couple of games where I was fuming that people were tackling him as I didn’t want him to go through it again, but he’s the opposite of paranoid.

He just wants to win. He still gets mad when decisions don’t go his way!”

In Schmeichel’s autobiography, One, he recalls showing Scandinavian visitors around Old Trafford, years after the incident, when out stepped Busst from the tunnel.

He was now a youth coach and had taken a group of kids to Old Trafford.

“It was a small moment of closure. What happened to him has never left me,” Schmeichel writes.

“It was the worst thing I ever witnessed on a football pitch and so close up that it almost felt part of me, if that makes sense.

“It may seem odd to say, but it sort of bonded me with David Busst.”

(Top photo: Laurence Griffiths/EMPICS via Getty Images)