For Mamadou Sakho, there is no satisfaction to be had in vindication. He has known for over a year he had done nothing wrong, and that the fat burner containing higenamine, for which he tested positive after helping Liverpool to Europa League progress beyond Manchester United, was not included on the World Anti-Doping Agency’s prohibited list. Uefa had admitted as much last July before, in the first section of a 104-page dossier released this week by its control, ethics and disciplinary body, the blame game over the player’s ban degenerated into petty finger-pointing between the governing body and Wada.

The real victim, the man who had been denied involvement in a cup final and a place in the host nation’s squad at Euro 2016, can only watch as the bickering shames the authorities. “I worked so hard to prepare myself for the European Championship, to help my country, to wear the France shirt in a tournament on home soil,” says Sakho. “Now I’ll never do that. Whatever they say or do, they cannot replace what they took away from me. My lawyer can see what happens next but, for me, I focus on other things. I have learned in life you should never look back over your shoulder, wondering what might have been. That is the past. Always look forward, at the next challenge. It’s life. Good and bad things happen, but my mentality is always to try and find a positive. It is the only way to be and, today, I am really happy.”

The last 13 months have tested that admirable mindset but, while his circumstances have shifted dramatically, Sakho is not one for changing. He is sitting in a backroom at The Hoxton, a hotel in east London’s trendy Shoreditch, a Crystal Palace loanee whose impact at Selhurst Park has helped wrest five wins from seven matches to ease Sam Allardyce’s team away from the condemned. A player more used to competing at the top end of a division has been a colossus – a leader and organiser, a warrior and inspiration – delivering everything Palace hoped he might. He has already achieved cult status among his adopted supporters, just as he had back at his parent club. On Sunday at Anfield, where he will be ineligible, he will watch on from the stands with both teams potentially, if privately, wishing they had him to plug the Sakho-shaped holes in their respective defences.

He admits to finding that scenario “awkward”, as if uncertain where his loyalties should lie, but it is just the latest twist to an unconventional year. Some of his setbacks have been self-inflicted – perceived tardiness on Liverpool’s pre-season tour of the United States, for which he apologised and was fined, helped fracture his relationship with Jürgen Klopp – but it was that routine drug test and the assessment of his urine sample undertaken at a Wada-accredited laboratory in Cologne which had nudged his career on its unexpected course. Sakho has never denied taking the product which contained higenamine and, after liaising with Liverpool, voluntarily made himself unavailable once Wada flagged up the positive test. Uefa would ban him for 30 days pending its own investigations, inquiries which ultimately saw it query whether higenamine should even be considered a prohibited beta2-agonist.

The centre-half’s last appearance for Liverpool had been as a goalscorer in a 4-0 victory over Everton. Less than a week earlier he had scored his side’s equaliser in that staggering Europa League quarter-final comeback over Borussia Dortmund. Sitting out what followed fuelled frustration and anger, born of a feeling of helplessness.

“But for me, the hardest moment was when I saw my Mum, my sister, my brother, my wife in tears … they didn’t understand the situation,” says Sakho. “That was difficult, seeing them upset. They were devastated, but I was there trying to explain to them I had done nothing wrong, and that everything would be alright. It would all be fixed. I was actually quite calm, quite peaceful, and just trying to reassure them. It was a time for me to be strong, and those who are close to me had faith. We knew that, eventually, I would be proved right.”

Crystal Palace won their first four games with Mamadou Sakho in the team, including the victory at Stamford Bridge over Chelsea. Photograph: PPAUK/REX/Shutterstock

He would be, but not before he had sat out the Europa League final, where Sevilla eventually overran Liverpool, and been overlooked for France’s squad for the summer’s championships. Missing out on a home tournament, whose showpiece would be staged just across the Parisian péripherique from where he grew up in Goutte d’Or, was cruel. Uefa’s disciplinary body would absolve him of any fault just 48 hours before the final. “I knew the ban meant I could not be picked, so I spoke with the manager Didier Deschamps and promised I would come to France’s first game, and to their last game too, and that I hoped that would be the final. It was. I visited the team hotel in Paris the day before the final to show my support. My ambition is still to play for my country at the World Cup in 2018, and regain my place.

“During that whole period I spent time with my family, and with my charity [AMSAK] in Senegal and Ivory Coast. I know I have been lucky in my life and can give something back. We visited an orphanage, a school for deaf and dumb children, and a juvenile jail, speaking to the kids there, giving them advice because everyone makes mistakes. The most important thing is to learn, to share knowledge. Doing that does feel like a release, a chance to put out a positive message and show that everyone can do something to help in his own way. I am lucky I can use my status in a positive way and give something back. You have to help people find a better level, always. The world can be better as a result.”

The hardest moment was when I saw my Mum, my sister, my brother, my wife in tears

Life at Liverpool was always a game of catch-up after the suspension, with the issues over the summer confirming the team had moved on. An August switch never materialised and he went into the final hours of the January transfer window uncertain where his future lay. Palace, 19th and defensively fragile, won at Bournemouth on the night of the deadline with Allardyce unsure whether he would end the game having secured Sakho or the Everton striker Arouna Koné as his second top-flight loanee. There were frantic post-match telephone calls conducted by the chairman, Steve Parish, and the manager in a corridor at the Vitality stadium as the clock ticked down, with Sakho waiting in the club’s office up in Soho. It was only after midnight that the Premier League ratified the defender’s arrival on a five-month deal.

“I’d only heard good things about the manager, and his being here helped make my decision easier,” says Sakho. “I spoke with [the Rubin Kazan midfielder] Yann M’Vila, who had worked with him at Sunderland last season, and he spoke so highly of the coach. He knows what he is doing, a top manager. Then there were people like Yohan Cabaye and Christian Benteke who told me this was a good team, a good club, and reassured me the move would work for everyone. Then there was the chairman. When he spoke to me on the telephone, he sold me his club. The passion with which he spoke about Palace … it really touched me. He transmitted that emotion to me in the telephone call. He’s a man of his word. He made me want to fight for his club.

“Look, it was still a big challenge, and a very different kind of challenge. But I’m so glad I did it. I get a kick out of being out on the pitch, playing football again. I am playing in front of big crowds, fans who appreciate my style of play. Ten months is a long time, but there’s no secret to hitting the ground running. No magic formula. I never stopped training and working really hard – at Liverpool, over the summer – and I’m proud of the effort I put in. It is paying off. It comes from my parents. They came to France 30 years ago from Senegal and it was so hard for them. They had to fight for everything, and they transferred this mentality to me. It is in my football, and it comes from the upbringing my parents gave me.”

Mamadou Sakho visited the France team during Euro 2016 to give them support and hope to represent his country at next year’s World Cup. Photograph: Dave Winter/Icon Sport via Getty Images

His seven matches to date have yielded 16 points, four clean sheets, a win at Chelsea, a first home success over Arsenal since 1979 and, most surreal of all, a celebratory jig of appreciation on the pitch from Sasa Curcic. Allardyce and Palace would be eager to retain his services if they retain their Premier League status, even with his asking price spiralling closer to £30m with each eye-catching display. “But you know, to talk about my future now is almost... égoïste. Yes, selfish. It is not the time. My only goal is the mission I have accepted at Crystal Palace, and I’m trying to help them succeed in what they need to do. I’m part of a team, and it’s the team that matters. Not my future. Not my contract. Not what happens next.

“It’s all about seeing Palace safe, and we’re not there yet. If I wear the Liverpool shirt again I will gladly. I have three more years of contract there. But if I have to stay at Palace, I would do that gladly too. I’m happy, I feel good here. I’m also someone who is ambitious, so I will let my agent deal with that in the summer and we’ll see where we are. If my future proves to be somewhere else … well, so be it. I’ll leave everything on my mother’s prayers.

“Sunday will be strange. I will be there with the Palace squad but, for this game, I’m in an awkward position. I have a foot in each camp. I still belong to Liverpool, a great team with a great manager, a club I really appreciate. I had this great relationship with the Liverpool fans and the players. But I now have that same relationship with Palace and their fans. The team as well. Everything has gone so well in the last few months … maybe this should be a case of ‘may the best team win’.”

Liverpool will always mean something to Sakho, as was demonstrated by his recent post on Instagram on the anniversary of the Hillsborough disaster. “But, today, I am with Crystal Palace,” he adds, “and we need those three points.”