Ole Gunnar Solskjaer excited by Amad Diallo potential

The initial fee for the winger is understood to be 21million euros (£18.7m) and add-ons could see it reach 41million euros (£36.5million), with Diallo now just awaiting visa clearance before travelling to Manchester.

"As a club, we have followed Amad for a number of years," United boss Solskjaer said. "And, having watched him myself, I believe he is one of the most exciting young prospects in the game.

"Manchester United has such a proud history of developing young players and everything is in place to enable Amad to reach his potential here.

"It will take time for him to adapt, but his speed, vision and fantastic dribbling ability will stand him in good stead to make the transition.

"He is a player with all of the raw attributes that are needed to be an important player for Manchester United in the years to come."

Considered one of the most exciting prospects in Italy, the PA news agency understands Diallo has been on United's radar since 2016 and consistently received the highest ranking when scouting that age range.

The head of academy recruitment, chief scouts and technical chief scout all ran their eye over the Ivorian, who has made five first-team appearances for Atalanta.

Diallo will not have to quarantine having been part of the Serie A side's Covid-19 bubble and is understood to be the first player signed and registered in the UK under the new post-Brexit regulations.

Pre-prepared paperwork for his Governing Body Exemption was sent to the Football Association in the early hours of New Year's Day and was approved the same day, leading Diallo to travel to Rome to apply for his UK visa.

"After waiting since the summer, it is finally a dream come true to complete my move to Manchester United," said Diallo, whose shirt number has yet to be revealed.

"I am hugely ambitious and there is so much that I want to achieve in the game; when I spoke to the manager I knew that I had joined the perfect club.

"This is a really exciting squad with so many great players, I can promise that I will work hard every day to learn from them and give everything to develop my game.

"The coaches have been fantastic since I signed, we have been in touch regularly and they have already given me a lot of great advice.

"I have had time to prepare for this move, both physically and mentally, and I have worked really hard to be ready to make the step up to this amazing club."