Argentina forward El Kun is the odd one out of a gaggle of ex Atletico Madrid forwards including Fernando Torres and Radamel Falcao.
Atletico Madrid is a hotbed for striking talents to make their name.
Former Manchester United forward Diego Forlan enjoyed a career renaissance at the Vicente Calderon, while the club were also responsible for their eagle-eyed spotting of Radamel Falcao and the development of Fernando Torres.
The latter two have since departed the club, with Falcao securing a high-profile and big-money move to AS Monaco and Torres moving to Liverpool, then Chelsea.
Another of their erstwhile stars, Sergio Aguero, transferred to Manchester City where he has built-up a reputation as one of the Premier League's most feared attackers, however, while the exits of Falcao and Torres were smooth, the club are seemingly embittered over the manner in which Aguero left.
"Everyone has left on good terms. Torres, Falcao… everyone except Aguero, who had a silly problem," said club president Enrique Cerezo. "He could've left as a hero [but] he left as a villain instead over something silly."
He added: "Any player who doesn't want to stay should pay the release clause and that's it. Our policy is clear. We don't want any players who are unhappy at Atlético. It hurts us when they leave, but if they pay the release clause it's not a problem."