World Cup 2014: Cristiano Ronaldo returns to Portugal training

Cristiano Ronaldo's left knee was strapped up as he took part in training with Portugal

Cristiano Ronaldo trained with the rest of the Portugal squad on Friday following fears his World Cup participation could be in doubt.

The Real Madrid forward, 29, had his left knee taped up as he took part in light drills.

The World Player of the Year limped out of training on Wednesday with an ice pack strapped to his knee.

His country, who lost their opening Group D match 4-0 to Germany, face the United States in Manaus on Sunday.

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