• Former United forward says Sanches turned down his old club • Bayern Munich’s new signing is lighting up Euro 2016 for Portugal

Nani has warned Manchester United that his former club may live to regret their failure to sign Renato Sanches. They were linked with the 18‑year‑old midfield prodigy from Benfica, having scouted him extensively, but they eventually stepped aside and Bayern Munich made the decisive move.

The Bundesliga club paid an initial £27.5m to secure Sanches on 10 May and the fee could rise to £63m with performance-related add-ons. If he continues to play as he did for Portugal in their Euro 2016 quarter-final victory over Poland on Thursday night, then Benfica will hit the jackpot. So, in a different sense, will Bayern and Portugal.

It is understood that the United manager at the time, Louis van Gaal, was not sufficiently convinced about Sanches, although it is common practice for big clubs to indicate they are no longer interested in a transfer target when it becomes clear he is set to join a rival.

Nani, who is at Fenerbahce, having previously been on United’s books for eight years, said that Sanches had the choice between Bayern and Old Trafford. And he suggested it was Sanches who chose Bavaria over Manchester.

Renato Sanches emerges in tepid Croatia tie to propel Portugal through Read more

“Renato would have been a great signing for Man United, I have no doubts,” Nani said. “But he had a choice – and the choice he made was Bayern Munich. I hope that he has made a good choice and that he is happy in his career but I think United will now know what a big player they have missed.”

The forward’s sentiment was echoed by another Portugal team-mate, José Fonte. “As a Premier League player myself – for me, they missed out on a very good talent,” the Southampton defender said. “Lucky Bayern Munich that they have him.”

Sanches was given his first start at this championship against Poland by Fernando Santos, having previously been used as a substitute. Sanches came off the bench on 50 minutes in the last‑16 extra-time win over Croatia to give a man-of-the-match performance while he also took the award against Poland, having scored his team’s equaliser with a fierce, deflected shot.

When the tie went to penalties, Sanches volunteered to take the second kick, following Cristiano Ronaldo, and the crowd at Marseille’s Stade Vélodrome held its breath as he made the walk to the spot. Everybody was thinking the same thing: it was quite a responsibility to be given to an 18-year-old. Could he handle the pressure? Sanches gave his answer with a nerveless conversion. He had even seemed to wait for an extra couple of seconds after the referee’s whistle had gone, before starting his run-up. The composure was extraordinary.

“The coach asked who wanted to shoot,” Sanches said. “Cristiano was first and I said I would be second. The coach had faith in me, and I was confident enough to ask to shoot. I was just thinking about scoring. I was very cool, very collected, and I did what I always do. I picked a side and put it in there.

“After the team, it is important to receive individual accolades. I was happy to be man of the match again, although only after the team does the individual player come. That is how you build up a CV. It is a lot of hard work to be this lucky. Sometimes, we are bound to be lucky because we have worked very hard.”

Sanches showcased his strength and technique, with his balance and quick feet standing out, but it was his fearlessness that underpinned the performance. “Renato isn’t scared to play in the big games and he isn’t scared to show his qualities against any opponent,” Nani said.

“It is good to see another young player want to be the star and want to achieve his dreams. You must be like that. You can’t be afraid of anything. Renato is a very confident player. He is very young but, already, he has a great personality for the game.”

Fonte said: “Renato has no fear. He just doesn’t care. He just asks for the ball all the time, every second. He has power, strength, the energy to run all day and great ability. It was a lot of responsibility, taking that penalty, and he showed no fear.

“He’s a cool kid in the dressing room, very quiet. He’s nice. He listens to the older guys and he wants to learn, which is good. It’s great to have him around and he will be the future of the national team, for sure.”