London: This was clearly a case of taking your job a bit too seriously. A Paris Masters security guard failed to recognise Rafael Nadal and refused to let him pass, albeit for a few minutes, since Nadal was not carrying his tournament card.

French television network Canal+Sport captured the hilarious moment on film, as Nadal made his way from the changing rooms to the courts.

The guard asked Nadal to show his tournament card, and refused to let the Spaniard through. "Hello sir, have you got your pass?" the security guard asked the world No. 1. Nadal replied: "I don't have it with me."

Once Nadal said his name, the guard's expression changed to one of a sudden recognition and he acquiesced and let him pass.

Nadal later pulled out of the tournament, on Friday, with a knee injury and was due to face Serbian player Filip Krajinovic in the quarter finals on Friday.

The incident was reminiscent of an episode involving Liverpool's Roberto Firmino at a Champions League tie against Maribor, who was asked for his Uefa accreditation on the way into the stadium.

The Brazilian forward had left it in the team bus and had to run back and get it.

In the final of the Paris Masters on Sunday, American Jack Sock won his first Masters 1000 title after beating qualifier Krajinovic.

Nadal, 31, widely regarded as one of the greatest tennis players in history, has won 16 Grand Slams, two Olympic gold medals, and four Davis Cups with the Spanish national team. The Spaniard had insisted he still expected to play at the year-ending ATP finals despite heavy strapping on his right knee during his last-16 win over Pablo Cuevas on Thursday.

However, in a press conference on Friday, Nadal admitted he could be forced to take an extended break. The Spaniard has been plagued by knee injuries during his career. "I have to pull out," said the 10-time French Open champion. "Of course it's a very tough decision for me, especially here in Paris, which has been the most important city in my career without a doubt. It's a tough situation but I tried my best. I did one treatment yesterday night to try and play today."

After wrist problems badly affected his 2016 season, Nadal had stayed fit throughout a remarkably successful 2017 campaign, winning two Grand Slam titles and returning to the top of the rankings.