Marquez's career was almost over in 2011

Four-time world champion Marc Marquez's career could have been over almost before it started, after suffering an eye injury that forced him to miss the end of his rookie season in the Moto2 World Championship.

Marquez, who wrapped up his second consecutive MotoGP title at Motegi in Japan, endured a worrying five months during which the 21-year-old was unsure whether or not he would ever be able to race a motorcycle again.

Doctors told the young Spaniard - who by then had won one title in the 125cc class - there was no guarantee the injury to his right eye would heal completely and Marquez admits it was the most difficult spell of his career to date.

"That moment was the most difficult moment in my career because it was a really long five months with that injury," Marquez said.

"We visited six or seven different doctors to try to understand the injury. They also said maybe it will be okay for the future, maybe not, we cannot guarantee to you that you will ride a bike again.

"Always I kept a positive mentality, even though I tried one day to ride a motocross bike with the double vision, but it was impossible," he added.

"After the [eye] operation I saw that it was getting better and better and thanks to that doctor that gave me the opportunity again to ride and enjoy my hobby.

"The lesson was that you need to enjoy the moment because you never know the future."

Marquez suffered the eye problems after falling on an unmarked section of wet track during practice at Sepang.