When will Luka Modric retire? Why Real Madrid hero might have plenty more in the tank despite approaching his 40th birthday

Modric turns 40 next year but the veteran is still proving his worth for Madrid. Much of his longevity is down to his work with physical trainer, Vlatko Vucetic, who has kept him in excellent shape over the years. The associate professor at the Faculty of Kinesiology at the University of Zagreb began working with the midfielder in 2012 and back then, the former Tottenham star wanted to play until he was 36. But it seems his physiology is quite remarkable.

Vucetic told Relevo: "He [Modric] asked me if I could help him. He wanted to preserve his condition, prevent physical setbacks and prolong his career. He wanted to play until he was 36. He set himself that goal."

The trainer added that despite Modric nearing 40, he has a metabolic age of under 30.

"It is true that he is neither 20 nor 30 years old; he is as old as the calendar indicates. But during all these seasons he has worked on prevention... and that is why his metabolic age is lower than his chronological age. My chronological age is 50 years old and my metabolic age is 35. His chronological age is 39 and his metabolic age is less than 30," he added.

Modric has proven that you can still have an excellent football career after 30, most notably as he won the Ballon d'Or at the age of 33 in 2018. He has won a hatful of trophies at Madrid and this month became the oldest footballer in history to play an official game for Los Blancos at 39 years and 47 days. His professionalism is an example for all who wish to prolong their careers.

Modric, who signed a contract extension with Madrid over the summer to extend his stay with the Spanish giants until 2025, is preparing to face his team's bitter rivals Barcelona in El Clasico on Saturday in a battle between La Liga's two top sides.