Man Utd must simply make Andre Onana upgrade as £16m price tag mooted for "best in the world" - opinion

Sometimes a football club doesn’t really appreciate what it has in a player until they leave, and Manchester United have learned the hard way.

Ruben Amorim inherited Andre Onana, who has never been able to bring his Inter Milan form to Old Trafford, and who has never looked like a £47.2m keeper. Not keeping David de Gea continues to look like a mistake.

United have been linked with Gianluigi Donnarumma, arguably the best in the world as things stands, but it is another who lays claim to this title who has been mentioned in a potential bargain deal.

According to beIN Sports, the Red Devils are seriously considering a move for Emiliano Martinez with Aston Villa willing to accept an offer as low as £16m - if Onana can be offloaded amid speculation linking him with a move to Saudi Arabia.

Man Utd consider “best in the world” Emiliano Martinez on one condition

Villa’s sporting director Monchi knows what it takes to be an elite level goalkeeper and gave a glowing insight into what United could be signing, if they persuade Martinez to jump ship: "He is an important part of the Aston Villa brand, it shows the growth of this club," Monchi told Olé.

"Having the best goalkeeper in the world, totally loved and involved with the day-to-day running of the club. Emi is more than our goalkeeper, he is a reference in the dressing room, the club, for our fans, within the Premier League.

"He is a reference, one of the team captains and an example. In recent years, he won the World Cup, the Copa America, became the best goalkeeper in the world and continues his daily motivation of wanting to be the best individually and as a team member.

"He is a perfect mirror, he did not rest on his laurels, he wants to improve day by day and push the team to grow. He is an easy person to deal with, approachable, who provides solutions within a discussion."

Encouragingly, United are setting their sights high when it comes to the No.1 position by targeting two of the best that there is. Both Martinez and Donnarumma have been key to their countries winning major tournaments and to them going deep in European football.

Who should United sign between Donnarumma and Martinez?

Surprisingly, what the eye test tells us about Donnarumma doesn’t equate to the statistics that Data MB presents to help analyse and compare goalkeepers.

Argentina’s No.1 comes out on top by some distance with even Onana looking like a better option – on paper. It is a position that is notoriously difficult to quantify though, and it doesn’t take United’s chief scout to work out who would be the more competent performer between the sticks.

In terms of shot stopping, both are imperious, although Martinez, at 32, isn’t going to get any better as he gets older, Donnarumma, 26, has yet to hit his peak. They also share similar leadership qualities and the sort of presence that is needed to carry the weight of expectation at Old Trafford and beyond.

The difference in price-tag is a relatively low £17m, but a long-term contract could see United solve a problem position for the next 10 years. Donnarumma is the only answer, even if the statistics don’t look good.