When a player makes their debut at 16, success isn't guaranteed, but a lot of potential is.
For Gianluigi Donnarumma, being brought into the squad aged 15 wasn't enough, and ever since his Serie A debut in October 2015 as a 16-year-old, he has held things down as Milan's number one ever since.
His unusual and equally as impressive ascent within senior football has flown under the radar alongside Milan's misfortunes of recent years.
And with those misfortunes, Donnarumma was naturally a victim of inconsistency during his adolescence. He's now 21, however, and is operating at new heights, quietly performing as one of the best goalkeepers in Europe this season as the Rossoneri make their way back to the top.
Donnarumma's form - and his contract expiring in this summer - has put Europe's top sides on alert, with Manchester United the latest to be considering a move for the Italian, according to Spanish outlet Fichajes.
And while as exciting and promising a coup it would be to land Donnarumma for any club, United need literally everything but a goalkeeper right now. Pursuing it would be a waste of time for all involved.
There is a growing sense around Old Trafford that David de Gea's time as number one is coming to an end. A drop-off followed the 2018 World Cup, and the Spaniard appears to be past his best. And while 30-years-old is no age for a goalkeeper, there are more future-proof options available.
Donnarumma solves that. At just 21, his career has barely even started at the top level, despite already having several seasons of experience under his belt as a first choice at a major side.
Along with invaluable playing time, he is a commanding figure and dominates his box by coming to collect crosses and barking out orders to his defenders. And for someone standing at 6'5, his athleticism to claw away low shots at full stretch is impressive. He currently leads the way in Serie A for most clean sheets in 2020/21, testament to his importance in Milan's upturn in fortunes.
There is an argument to suggest that his CV so far, which boasts 200 Serie A appearances, makes him a more sensible option moving forward than both De Gea and even Dean Henderson - the latter of which is struggling to find those precious minutes anyway.
For all of De Gea's criticisms, nobody can deny that he is genuinely world class on his day. Henderson is viewed as one of the most promising young goalkeepers in the game and his long-term contract reflects that. We haven't even considered Sergio Romero yet; he's rotting as third choice at the Red Devils, which tells you all you need to know abut the strength of their goalkeeping department.
Adding Donnarumma to a roster which already sees Romero on kit washing duty with Lee Grant would be seriously greedy and, truthfully, a waste of resources. Like Vince McMahon signing every wrestler imaginable to WWE just to stop them from going elsewhere, it might seem smart at first, but it just creates a bigger logistical headache.
United have more pressing issues towards the back-end of the pitch. Instead of shelling out more wages on another goalkeeper - and getting into bed once again with Mino Raiola, who represents Donnarumma - the funding and scouting must instead be used to find a central defender and a holding midfielder. Using the summer to determine who will be United's number one out of De Gea and Henderson going forward would also do more to shore up Ole Gunnar Solskjaer's defence than signing Donnarumma.
He is a supremely talented keeper with a bright future that perhaps United should keep a loose eye on. But Donnarumma is the last thing they need right now, and signing him benefits nobody involved.