For many modern-day fans around the world, the debate over who is the greatest player of all time comes down to two names: Lionel Messi or Cristiano Ronaldo? Jose Mourinho, though, believes he has worked with a player of even greater ability.

The ever-controversial Roma coach is more qualified than most to weigh in on the matter, having coached against Messi on a host of occasions and worked with former Manchester United Ronaldo for three seasons at Real Madrid, winning a La Liga title together.

Boasting no less than 12 Ballon d'Or trophies between them, it's easy to see why Messi and Ronaldo have been considered the top contenders for the GOAT crown for a number of years.

For Mourinho, however, injuries "killed the career" of the greatest player had ever seen play in his lifetime.

The 59-year-old Portuguese worked with Ronaldo Fenomeno during his outstanding 1996/1997 campaign for Barcelona, in which he scored 47 goals in 49 games for La Blaugrana.

Mourinho, who served as an assistant to Sir Bobby Robson at Camp Nou at the time, told Livescore, via The Sun: "Cristiano Ronaldo and Leo Messi have had longer careers, they have remained at the top every day for 15 years.

REGGIO NELL'EMILIA, ITALY - NOVEMBER 09: Jose Mourinho, Head Coach of AS Roma looks on prior to the Serie A match between US Sassuolo and AS Roma at Mapei Stadium - Citta' del Tricolore on November 09, 2022 in Reggio nell'Emilia, Italy. (Photo by Alessandro Sabattini/Getty Images)

"However, if we are talking strictly about talent and skill, nobody surpasses Ronaldo, El Fenomeno.

"When he was at Barcelona, I realised that he was the best player I'd ever seen take to the field.

"Injuries killed a career that could have been even more incredible, but the talent that that 19-year-old boy had was something incredible."

23 Oct 1999: Ronaldo of Inter Milan celebrates his goal against AC Milan during the Serie A match at the San Siro in Milan, Italy. Mandatory Credit: Claudio Villa /Allsport

At his peak, Ronaldo Fenomeno was simply electric. His insane pace combined with an unmatched eye for goal persuaded Inter Milan to part with a world-record fee of £25m in 1997 after he'd spent just one season at Barcelona.

It was at the San Siro in April 2000 that the Brazilian would rupture a tendon in his right knee. He would never quite be the same player again - and the insane talent that Mourinho raves about was lost to the world.

With that said, he still went on to have a career that many top players would love to be able to call their own.

16 Jun 1998: Ronaldo of Brazil on the ball during the World Cup group A game against Morocco at the Stade de la Beaujoire in Nantes, France. Mandatory Credit: Shaun Botterill /Allsport

A two-time World Cup winner (1994 and 2002), Ronaldo Fenomeno also scooped a pair of Ballon d'Or trophies (in 1997 and 2002).

Granted, he can't boast the same number of trophies and individual accolades as Messi or his namesake, Cristiano. However, to those that saw him in his prime - such as Mourinho - 'R9' certainly belongs firmly in the GOAT debate.

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