Cristiano Ronaldo's training session ended early on Thursday after he left the field with an ice pack over his left knee, the AP reported.
The Portuguese star, who had been battling patellar tendinitis in his left knee, practiced for only 15-20 minutes with his national team. The AP reported that he took part in exercises but skipped the drill portion of the session.
He then went off to stretch on his own and sign a few autographs. Ronaldo had missed two weeks of practice leading up to the World Cup while battling both the tendinitis and a thigh injury. Earlier this week, he was reportedly cleared to start the World Cup opener against Germany on Monday.