The Argentine played alongside Maradona for their national team, now they are in opposite dugouts.
Calderon adds spice to the Pro League
They were the awesome trio who spearheaded one of the most exciting youth teams of the 20th century.
At the Fifa Under 20 World Cup of 1979, one 18 year old caught the eye above all and stirred observers to call him by the superlatives that would accompany him for the next decade.
The winning Argentina from that tournament in Japan made an international reputation for one of football's legends.
You will know the one: He is currently the head coach of Al Wasl.
Alongside Diego Maradona in that gifted set of cadets were two others who would export their talent. Ramon Diaz, a diminutive striker, would hear himself labelled "another Maradona" when signed by a series of Serie A clubs.
It was said of the third gifted attacker, Gabriel "Gaby" Calderon, that he possessed a left foot almost as charmed as the young Maradona's. It is a fair assumption that nobody back then would have imagined Maradona and Calderon celebrating their 51st and 52nd birthdays, respectively, as rival managers in the Pro League.
Calderon, who took over at Baniyas last week, hardly needed his old colleague and compatriot's advice on coming to work in the region. He already has a distinguished record as a coach in the Middle East.
After spells managing clubs in France and Switzerland, two leagues that had featured in his playing career, he took the job in 2004 as the national coach of Saudi Arabia, a notoriously insecure post.
His tenure would eclipse in success and longevity of most of those who had preceded him. In the lead-up to the 2006 World Cup, building a team praised across Asia for its enterprise and organisation, he established a new record for the Saudis for qualifying in style.
Naturally he hoped he would then be the man in charge at the finals in Germany.
"It was strange," he would later say, "that the people in charge decided to get rid of me."
Strange, but no so unusual: When Calderon accepted the Saudi appointment he was the 16th man to do so in a dozen years.
He then had a stint in charge of the Oman national squad, and it was noted in some difficult ties that he had raised standards. His reputation in Saudi football remained high, and he returned there as a club manager, winning league titles with Al Ittihad and with Al Hilal.
His wide experience and respected methods have brought him regular invitations to contribute to Fifa's coaching think tanks.
As a footballer Calderon had the kind of vision and poise that suggested a strategist in the making.
He operated to the left or in the centre of the attack, but was as comfortable in the space between the forward line and midfield.
He had emerged as a teenager at Racing Club, thrived at Independiente and soon after his first World Cup, the 1982 tournament in Spain - by which time he, Maradona and Diaz had all graduated to the senior squad - he earned a transfer to the Spanish top-flight, with Real Betis.
He was hugely popular there, a reliable goalscorer - 38 in 131 matches - and a generous provider of assists.
His move to Paris Saint Germain, at 27, was also a success, though his role would be more that of creator than finisher. He helped PSG to a runners-up spot in the French league in 1989, and earned himself a place in the Argentina squad for the 1990 World Cup - both he and Diaz had missed out on the Maradona-led triumph in Mexico in 1986 - where he would play a significant part in the final.
Argentines still bemoan the fact that West Germany's Lothar Matthaus was not punished for bringing down Calderon in the penalty area during the 1-0 German win in Rome. Maradona felt especially incensed. That's one of many shared stories the two can reflect on together when they meet as rival managers in the new year.