‘Take that.” Roy Keane stood over Alf-Inge Haaland, lying in a crumpled heap never to play a full game again, delivered his message and walked away without remorse. As reactions go – as tackles go too, if Keane’s infamous lunge can be called that – it could hardly have been more different to that of Son Heung-Min, who broke down in tears after André Gomes broke his ankle last week. On Wednesday night, Son dedicated his opening goal against Red Star Belgrade to the Everton midfielder. “I’m so sad this happened and that I was involved with this situation. I feel really, really sorry about this accident,” he said.

Be clear: Gomes is the victim, unable to return to playing for a long time, if at all. But Son’s reaction was a reminder that for players involved in serious injuries it is not always so easy to walk away. There’s guilt, even if there is no blame, a backlash, a desperation to atone in some small, insufficient way.

John Fashanu, who fractured Gary Mabbutt’s skull, leaving him with horrific injuries, says Ryan Giggs sent signed pictures when an accidental collision ended his career. Although, asked if injuring a player is hard to live with, Fashanu also responds bluntly: “It’s not the end of the world, don’t blow it out of proportion: ‘Oh my God, I’m going to commit suicide, I can’t eat all day.’ No.”

Casiraghi didn't blame me for ending his career ... but his wife did Shaka Hislop

Yet live with it, many must. For a lot of players, that moment never goes away entirely. Even Keane had to revisit it, not just unable to walk away in the end but actually walking back into it. He claimed the ghost writer of his autobiography, Eamon Dunphy, had taken “artistic licence” when describing the scene as more like an assault than an attempt to win the ball. It was, he and Roddy Doyle wrote in a subsequent book, as if he had “killed someone”. Not that he showed contrition: this was about responsibility, rather than regret.

Son’s remorse was clear immediately. He was shocked by what he saw. Some injuries can’t be unseen. One of the lasting images of Coventry City’s David Busst suffering a broken leg at Old Trafford, shin bone puncturing his calf, soaking the turf in blood, is Peter Schmeichel walking away horrified, unable to look. The goalkeeper later admitted: “Everyone went numb.”

Andoni Goikoetxea: ‘Every time I talk about [the Maradona foul], I feel like I’m defending myself all over again.’ Photograph: Mark Leech/Offside/Getty Images

The Korean’s reaction also recalled the broken leg suffered by Deportivo de La Coruña defender Manuel Pablo. As he looked down following a tackle with Celta Vigo’s Everton Giovanella in a Galician derby, Manuel Pablo said he saw his leg “hanging there”, as if on a hinge. Giovanella did too, head in his hands, tears streaming. Still crying, afterwards he said: “I want him to know I never, ever, meant this; if I could swap places with him, I would.” Two days later, Giovanella travelled 160km for a hospital visit. “He was in a bad way,” he said. And he here is Manuel Pablo – it was Giovanella in a state, just as it was Everton players heading to the Spurs dressing room to console Son.

Giovanella and Manuel Pablo became friends; for others, it is different. Shaka Hislop recalls visiting Pier Luigi Casiraghi at a King’s Cross hospital after an accidental clash which ended the Italian’s career. Casiraghi was happy to see Hislop. His wife, though, wasn’t. “She held me to blame. I understand that, as a significant other, that’s how you see things,” the former West Ham goalkeeper says. “He didn’t blame me. I said I hoped to see him on the field soon, but that never came to pass.”

And then there is Andoni Goikoetxea, who broke Diego Maradona’s ankle in 1983. He told the Observer: “Every time I talk, I get the feeling I’m having to defend myself again,” he says. Just this call, 36 years on, is proof it never goes away entirely. “It was a tough tackle in a place I shouldn’t have done it,” he admits. “After the game, Barcelona’s Víctor Munoz said: ‘Don’t worry, I don’t think it’s bad.’ But that night, our coach, Javier Clemente, told us. It was a hammer blow. I knew what was coming. You try to sleep, you can’t. I spoke to him, called him. I had a bad time, so did my family. It was hell at home: the press came, the phone rang constantly, I had to leave for three weeks.

“When he joined Sevilla a few years later, I spoke to their press officer and asked him to arrange a meeting. We met for a coffee, chatted, talked about the family. I don’t remember the chat well; I’m not even sure we talked about the injury.” Everyone else did. “The first game after in France, they seemed disappointed that I wasn’t the devil with a forked tail. I went to England and the Sun’s front page called me The Butcher of Bilbao.

“Not long ago, the Times said Mr Goikoetxea is the most violent man in sporting history. I don’t recognise myself in that description. It doesn’t hurt, I don’t care, but it is unfair. I was an international, played for 16 years, scored more goals than any defender in Athletic’s history: 44. And people think all I ever did was injure Maradona; they only know me because of him. Years later, I’m still talking about it.”

Yeah, sorry about that. Goikoetxea placed the boots he was wearing in a glass case, like a trophy in a cabinet. “But it’s not what people think,” he insists. “I wore those boots in two games. One is the Maradona game and the other is Lech Poznan in the European Cup four days later. It was a special game. I’d just been given a long ban, we’d been handed the trophy for the previous season’s league title, I scored the first, we won 4-0, came back from a 2-0 in the first leg, and my teammates carried me off on their shoulders – which I’d never seen before. They knew my emotional state, how hard it had been.

“I wasn’t going to play for a long time and I thought: ‘I’m going to keep these boots’. They have a huge sentimental value; they’re a symbol, a powerful message. They’re what football is: sadness and happiness, good and bad, the beautiful and the ugly. Those boots are football.”