Argentina's World Cup-winning coach Cesar Luis Menotti says Lionel Messi has benefited from playing in a superior team to Cristiano Ronaldo.
The Barcelona and Real Madrid stars are expected to be among the final three Ballon d'Or nominees once again this year, having shared the prize between them since as far back as 2008.
Ronaldo lifted the Champions League for the third time in his career in May, but has often seen his Madrid side overshadowed by Barca, who have won eight LaLiga titles and four European titles since Messi's debut in 2004.
But Menotti, who guided Argentina to their first World Cup triumph in 1978, believes his compatriot has spent his career playing for a stronger side.
"Messi would not have been the same at Real Madrid," he told Fox Sports. "He started at Barcelona with [Andres] Iniesta, Xavi, Ronaldinho. A team that Cristiano Ronaldo never had.
"Cristiano always worked like a hero. He's a massive player, and maybe a great guy. But he works like a hero and he gets 50 goals.
"Messi has grown an enormous amount from the first day until now. He went from being a clinical striker to a more creative game, where he has another role."
A dispute between Argentina and Barca has threatened to emerge due to the knee injury sustained by Messi in the 1-1 league draw with Atletico Madrid.
National team coach Edgardo Bauza appeared to question Barca's commitment to safeguarding Messi's fitness, although he later claimed his remarks had been taken out of context and said he was eager to avoid "a fight" with the club over the player.
Menotti agrees that care must be taken to prevent the 29-year-old becoming overzealous in his performances and risking further injury problems.
"There are good players, very good players, and then the magicians, who you have to leave to one side - like Messi, Pele and [Diego] Maradona," he added.
"Messi is a player who wants to win everything, wherever he plays. What you have to do is be careful that he doesn't overdo being the best every 10 minutes."