Pierre-Emerick Aubameyang was given the perfect example to hone his craft when starting out at AC Milan alongside Ronaldo - though he admitted the Brazilian legend was "a bit fat by then".
The original R9 spread terror throughout defences across Europe and on the international stage, earning him the nickname Il Fenomeno (phenomenon), having fired Brazil to their World Cup triumph in 2002 - his second winners medal - as well as developing his reputation as one of the greatest striker's in history at Real Madrid, as well as spells at PSV, Barcelona and Inter Milan.
However, injuries, weight issues and age had taken their toll on the three-time FIFA World Player of the Year by the time he pitched up at San Siro aged 30. Madrid agreed to sell Ronaldo to Milan for a cut-price €8million fee in January 2007, though his powers were significantly on the wane.
Ronaldo scored just nine times in 20 appearances for the Rossoneri, before eventually joining Cruzeiro 18 months later. His time at Milan was cut short several months prior by a cruel recurrence of the knee ligament injury that had blighted the early years of his career.
Yet his quality was still evident to a young Aubameyang coming up through the ranks, who used the opportunity to train alongside one of the game's all-time greats to glean as much insight as he could.
“The team was really strong, to tell the truth," Aubameyang said. “Ronaldo, Paolo Maldini, Alessandro Nesta… at that time I was very young.
HAVE YOUR SAY: Where does Ronaldo rank among the greatest all-time strikers? Let us know in the comments below.
“I was just trying to improve and looking at him [Ronaldo] to learn as much as I could. To tell the truth, he was a bit fat by then! But he was still the best."
Despite struggling to find the net with the same consistency he had shown earlier in his career, Aubameyang recalled how Ronaldo would not let his fitness issues overshadow his goalscoring capabilities.
“I will always remember when Carlo Ancelotti had a go at him about his fitness, he said, ‘What do you want me to do, run or score goals?’
“Ancelotti said, ‘score goals’, and the next time Ronaldo scored twice! That is part of the character and as a striker you need that because you have to be strong mentally.”
Aubameyang failed to make the breakthrough at Milan despite impressing in their academy, spending three seasons out on loan in France before he was eventually sold to St Etienne and going on to make his name at Borussia Dortmund and flourishing in subsequent spells at Arsenal and Barcelona.
Now 33, the Gabonese international is embarking on a fresh chapter at Chelsea and grabbed his first goal for the club in Saturday's 2-1 over Crystal Palace at Selhurst Park. Aubameyang swivelled superbly on the edge of the box to fire hard and low into the bottom corner to draw Chelsea back level, before Conor Gallagher's late winner sealed the points.
