This is not a good sign. Cristiano Ronaldo was thought to be on the road to recovery from his tendinitis in time for the World Cup, but he left Portugal's Thursday practice early and was seen with an ice pack on his left knee. According to reports, he only lasted about 15 to 20 minutes.
Ronaldo played in Portugal's friendly against Ireland on Tuesday - a 5-1 victory - which was his first game since the Champions League final. He has been struggling with injuries in his left leg but was cleared to return to training.