Last season, José Callejón cemented himself as one of the most dangerous players in Italy’s Serie A at Napoli. He scored 17 goals as part of one of European football’s most prolific attacks; Maurizio Sarri’s side scored an impressive 94 league goals.

Right-winger Callejón also chipped in with 13 assists in his 49 outings in all competitions last term as Napoli, spearheaded by Dries Mertens in attack, finished the league season in third place. The little Belgian scored 34 goals, attracting the interest of Europe’s elite, and the riches of the Chinese Super League, in the process.

Callejón began his career at Real Madrid; he was the club’s reserve team top goal scorer for the 2007-08 season, but with first team chances at the Santiago Bernabéu limited, he joined fellow La Liga outfit Espanyol the following summer.

After making close to a century of appearances for the Catalans, he re-joined Jose Mourinho’s Real in 2011. He was often restricted to substitute appearances as he played second fiddle behind Cristiano Ronaldo, but still scored an impressive 20 goals in 77 games. Former Napoli manager Rafael Benítez saw potential in Callejón and signed him in 2013; he has since won the 2013-14 Coppa Italia (finishing as the competition’s top scorer) and the 2014 Supercoppa Italiana.

Callejón is not the first, and probably will not be the last, Real Madrid academy graduate to win trophies away from the Spanish capital. Juan Mata and Alvaro Negredo have both won the English Premier League title having struggled for first-team opportunities at the Bernabéu – it is often forgotten that they once wore the famous white shirt.

But for every success story, there is an out of mind player that was once touted as the club’s next superstar. Javier Portillo scored 150 goals for Real’s youth sides in seven years, but during the ‘Galácticos’ period, was never given a real chance in the first team. Franciso Pavon was earmarked as a club stalwart for years to come after his emergence in the early 2000s, but was soon shown the exit door and left for Real Zaragoza. He retired as a free agent at the age of 33, after embarrassingly becoming eligible for unemployment benefits.

Callejón will be no stranger to the ruthless nature of Real’s transfer dealings. Not because of his own departure to Napoli, but because of the treatment of his often forgotten and anonymous identical twin brother, Juanmi.

The Callejón brothers spent their early years as professionals at Madrid, side by side. In the same transfer window as Jose’s move to Espanyol, Juanmi moved to Real Mallorca, who were also in La Liga. However, as Jose made a name for himself in Spain’s top flight, the same could not be said of his twin; Juanmi made just one appearance for Mallorca before being loaned to Albacete in the Segunda Division.

An uninspiring spell in the second tier preceded an equally unimpressive three years spent playing for Córdoba, Hércules and Levadiakos of Greece. In 2013, after playing just ten games in the Greek Super League, Juanmi left Europe and moved to Bolivia’s Club Bolívar. In the four years he spent in South America, he amassed more league appearances (142) than he achieved in total at his previous six clubs.

Boasting the same athletic, tall frame, with the same distinctive gelled hairstyle, it is amazing how different the careers of the Callejón twins have panned out. Jose has played for Spain, and is a serious contender to be in Julen Lopetegui’s national squad for the 2018 World Cup in Russia.

At the same time as Jose’s Napoli were in the middle of an impressive 14-game unbeaten streak in January 2017, which included a 7-1 demolition of Bologna, Juanmi was finalising a deal for yet another transfer. He struggled to regain his place back in Bolívar’s starting XI after being sent off for fighting in a match against Club Real Potosí.

He moved to Al-Ettifaq, who had just earned promotion to the Saudi Arabian Pro League; he appeared only 13 times for his new side in the second part of last season, scoring just one goal. The club’s 2016/17 top scorer was striker Hazaa Al-Hazaa, who scored just six goals – a stark contrast to the success of Mertens who starred in the same role playing alongside Jose for Napoli.

Three managers oversaw the last campaign at the Prince Mohamed bin Fahd Stadium. Juan Garrido, who signed Juanmi, left after a six-game winless run that included five defeats having replaced Djamel Belkacem. Eelco Schattorie arrived late in the season and did not fare much better, leading Ettifaq to just one win out of seven. The club narrowly avoided a relegation play-off by one point, and finished the season with just 27 points from 26 games; Juanmi’s position in Saudi Arabia was a far cry from that of his twin brother’s back in Europe. Having turned 30, a move back to one of Europe’s top leagues now seems unlikely.

Ettifaq’s lowest home attendance last season was a meagre 506, for a match against Al-Shabab in May. By contrast, 56,695 fans crammed into the San Paolo to watch Napoli’s UEFA Champions League tie against Real Madrid, which saw Jose face his former club. It is amazing to see how different the careers of two identical twin brothers, who graduated from Real’s academy before moving to two La Liga clubs in the same transfer window, have turned out.