Duk’s turbulent spell at Aberdeen came to an end in January as he transferred to Leganes.
The Cape Verde international moved to the La Liga side in a deadline day deal, reported at the time to be worth £600,000.
But we revealed that the actual fee Leganes paid for Duk was £400,000, with Aberdeen due only half of that as Benfica had a 50% sell-on clause from when he moved to Pittodrie.
The Dons will then get another £50k if the Spaniards avoid relegation from the top flight, currently just one point above the drop zone.
After a phenomenal start to life in the Scottish Premiership in his first campaign, the 24-year-old dipped last season amid speculation of interest in his services. He then went AWOL at the beginning of this campaign, before returning, apologising and being welcomed back into the fold.
But he now embarks on a new adventure in Spain while Jimmy Thelin goes forward with his own new players.
Leganes fans react to Duk debut
Duk was handed his Leganes debut on Sunday in a relegation six-pointer against Valencia.
The opponent started the day in the relegation zone and four points behind Los pepineros, but clawed it back to just one with a 2-0 home win.
The former Aberdeen star didn’t start the game but was brought on as a sub for Miguel de la Fuente, as manager Borja Jimenez tried to make positive changes to influence the outcome.
And while Duk didn’t score or contribute to any sort of comeback, he did seem to make a good impression on fans who had already been excited for his arrival.
After Leganes posting a photo of the debutant to social media with the caption ‘new number 18, supporters piled in with praise.
One said: “This 18 has touched the ball more in 20′ than Haller in 6 months.”
Another wrote: “Desire to see him at Butarque.”
While this one said: “He did more in 10 minutes than many in 75.”
While another was clearly very excited and added: “Duk, Duk, Duk, Duk, Duk, Duk, Duk, Duk, Duk.”
Aberdeen could benefit further from Duk sale
On top of the £200k lump sum we mentioned and the potential £50k if his side avoid relegation, the Pittodrie could benefit further.
That’s because they negotiated a five per cent sell-on clause on the deal, meaning if Leganes were to sell him for £1million, the Dons would get £50,000.
It comes after Benfica had a 50 per cent sell on in the initial deal, with Aberdeen not paying anything up front.
Duk said at the time: “I have a contract with Aberdeen for two more seasons, until June 2025.
“Benfica has 50% of my transfer. But right now I’m very happy here. I’m enjoying it a lot and I’m in no rush to leave here.
“I’m focused on Aberdeen and what I want is to keep scoring goals.”