It was a chastening experience for a young and inexperienced player. Three down in one of the biggest games in world football and hooked at half time.

It was 2022 and Amad was on loan at Rangers, still searching for consistency and a run of games. He'd scored on his debut for the Glasgow giants a few days earlier but 45 minutes into the Old Firm derby with Celtic and he was hauled off.

Some observers felt Amad appeared stunned by the intensity of the contest and some questioned his attitude after a lacklustre 45 minutes. In truth, he never quite got going north of the border.

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It's a far cry from his standing these days as he prepares to go up against his former club in a mammoth clash that is crucial for a floundering Manchester United's season. Amad has almost single-handedly been trying to resurrect it in recent weeks but Ruben Amorim's men continue to struggle in the Premier League and the Europa League represents their best avenue for silverware and a route back into continental competition next season.

Amad is one of the first names on the teamsheet and his rapid rise over the past year can be traced back to what came after Rangers.

Having returned to Old Trafford pondering what might come next, the youngster joined Sunderland in the Championship under Tony Mowbray. A manager with a track record of trusting and improving young players plus a club thrilled by the style of play Amad can offer and the winger was transformed.

He spearheaded Sunderland into the play offs with a string of stunning showings and glorious goals. Promotion eluded the Black Cats but Amad had gone from being questioned to providing answers.

Mowbray played his part in nurturing talent but the now West Brom boss knows it was the player who deserves the platitudes.

“Amad gives me the credit for giving him confidence to show people his talent,” Mowbray said, speaking to The Athletic this month. “But he did it himself. I texted him the other day. He’s so humble.

“I didn’t know him at first. I asked the analyst to show me some clips to see what he was all about. He wasn’t the Amad Diallo you see now. He was quiet, shy, mixed in with the French kids. But you can’t hide talent.

“He was strong. With his hips and backside, he could hold people off and the ball was stuck to his left foot. There was one training session when no one could get the ball off him and he was smashing it in the top corner. It’s not clever management to put them in. You just have to. Their talent is telling you that.”

His talent is telling Amorim the same thing. Having struggled to win over former United chief Erik ten Hag despite that wonderful winner against Liverpool in last season's FA Cup, Amad has become a fixture for the Reds this term.

Amorim has full faith, just as Mowbray did. Other managers haven't had the same belief.

"I think he has talent," said Amad's Rangers boss Giovanni van Bronckhorst when discussing the winger in 2022. "He came in in the winter break, he had some good moments but also some moments that were not so good."

That was hardly a ringing endorsement and Amad's time at Rangers saw more substitute appearances than starts. That Celtic contest stuck with him even if there were flashes of what he could offer.

"At Celtic he almost looked like a rabbit in the headlights," former Scotland forward Steven Thompson said. "That set him back, I think, both from a kind of mental point of view and the fact that then Giovanni van Bronckhorst didn't use him as much.

"When you look at Amad and the amount of games he's played as a professional footballer, he's hardly played any. He's learning. What happens to him next? I guess we'll find out."

And find out we did. Amad has gone from being a spare part at Rangers to a vital cog at United. You wouldn't bet against him issuing the Ibrox club with a reminder of that talent tonight.