Dundee United could eventually rake in over 6 million from Ryan Gauld’s transfer to Sporting Lisbon if the superkid is a big hit in Portugal.

The Tangerines will definitely bank 2.2 million by way of an initial transfer fee for the 18-year-old, who finally signed for Sporting around 1 am on Wednesday.

If he claims a first-team spot, that will quickly rise to well over 3 million by way of add-ons.

And with the Portuguese club including a 60 million buy-out clause in his new six-year contract, that figure would more than double if he moves to an even bigger club in the future.

That’s because United have retained a stake in Gauld meaning they would be due a sizeable chunk of any future transfer.

They could also earn more if Sporting decide to open negotiations to buy out United’s interest at some point.

But should Gauld shine, another move would be a distinct possibility.

In the past, Sporting have not been slow to cash in on valuable assets and players like Cristiano Ronaldo, Luis Figo and Paulo Futre have all been moved on for massive fees.

The Scotland U/21 star’s switch was only finalised after an evening of tense negotiation in the Portuguese capital.

Sporting had planned to unveil Gauld at a gala event to celebrate the club’s 108th birthday and introduce the squad for the coming season.

Legal technicalities, though, caused the first delay and even once the clubs had reached agreement, things did not run entirely smoothly.

His medical was a formality but talks on personal terms took longer than expected, meaning it was one in the morning before he put pen to paper.

His six-year deal will see him triple his wages to around 5,000 a week.

While that’s a substantial amount for a teenager, it’s also an indication football reasons were his main motivation for going overseas.

There are players in the Premiership here on bigger wages and had he decided to hold out for a move to England, Gauld could have more than quadrupled what he’s getting at Sporting.

United announced his departure in a brief statement.

“Subject to the usual formalities, Dundee United confirm the transfer of Ryan Gauld to Sporting Lisbon, for an undisclosed fee, was completed last night.

“Everyone at the club wishes Ryan the sincere best wishes in his future career.”