FIFA World Cup 2014: Cristiano Ronaldo's training session ended in just 20 minutes with an injured left-knee

Ronaldo looks dejected during the training session that end in just 20 minutes with an injury.

Portugal's World Cup preparations suffer a major blow after Cristiano Ronaldo's training session was cut-short due to a persisting tendinitis in his left-knee. Ronaldo did some physical exercises with his teammates for about 20 minutes but could not continue as he left with an ice-pack to nurse his injury.

Ronaldo, the 2014 Ballon d'Or winner, remains Portugal's most important player ahead of their World Cup campaign. The Portuguese has been struggling with an injured thigh and a tendinitis in his left-knee for more than a month now, and remains one of the biggest concerns ahead of their World Cup campaign.

Paulo Bento's team faces Germany in their opening game on 16th of June against Germany. As of now, no official statement has been released on the fitness of the Portugal forward.