Stefan Savic says Joao Felix can claim the Ballon d'Or one day but has insisted that his colleague must first win something with Atletico Madrid.
Atletico forked out a club-record fee of €126 million (£115m/$153m) to bring Felix to Wanda Metropolitano from Benfica in July 2019.
The Los Rojiblancos won the race for the Portuguese playmaker's signature ahead of a host of top European clubs, including Spanish rivals Real Madrid, but he has taken time to adapt to his new surroundings after a rapid rise to prominence in the Primeira Liga.
Felix was only able to show glimpses of his talent during his first season on Atletico's books, scoring nine goals in 36 matches as he found himself in and out of Diego Simeone's starting XI.
The 21-year-old has, however, taken his game to new heights at the start of the 2020-21 campaign, helping Simeone's men storm to the top of La Liga in the process.
Felix has found the net five times in 10 domestic outings while also recording three goals in five Champions League appearances, having developed an aggressive streak to complement his impressive creative skills in the final third.
Savic says the Portugal international was the subject of unfair criticism at the start of his Atletico career, and has predicted that his talented young team-mate can go onto win football's most coveted individual prize if he continues on his current trajectory.
“He is a different player, something that we did not have in the squad. He is still a young boy, he has room to grow and you have to leave him alone," the Montenegro international defender told Goal.
"You have chosen the best possible club to grow. He has a great future and if he continues like this, I have no doubt that he can be a great player or a Ballon d'Or winner, but before that he has to win something with the club."
Savic went on to play down Atletico's title chances, stressing that it is still far too early to get carried away by their position in the Liga standings.
“We are very good, but we don't like to talk now about how the League will end. It is too early to make calculations to win the League," he said. "We are very good, we have won eight games, but we did not get out of our 'game by game' and hopefully when the year ends we can win a title.
"Hopefully we can continue in this line until the end of the season."
Asked if it would be a missed opportunity if Atletico fail to win their first domestic crown since 2013-14, Savic responded: “It is not a failure if we don't win the league, for sure. There are other very good teams. No one can force us to win anything. The team tries every year to win titles. That's how it is.
"We have won the Europa League, we have won the Super Cup, we were very close to winning the Champions League and we are going to fight all the titles.
"This team has a lot of potential but it is still early to know how this season will end."