Ronaldo playing for Portugal

Ronaldo, who featured in Portugal's heavy 4-0 defeat to the Netherlands, suffered a reccurrence of his knee injury in training which hampered him throughout last season.

Doctors have reportedly told the 29-year-old that the injury will rule him out for the remainder of the tournament.

According to El Confidencial, Dr Jose Carlos Noronha advised Ronaldo to rest his knee for around two months after an MRI scan showed significant pressure on his tendon, risking a tear that could end his career. However, conflicting reports from Portuguese newspaper Record say that Noronha categorically denies telling Ronaldo not to play.

But the Real Madrid forward is ready to play through the pain barrier regardless and may have painkilling injections for the crucial game against the USA on Sunday.

Cristiano Ronaldo's knee was heavily-strapped in bandage in training ahead of the USA game

He reportedly told the Portuguese medical team: "I'm the one that says whether I'm playing or not."

The Ballon d'Or winner is Portugal's all-time top goalscorer with 49 goals from 112 caps, and scored eight goals in qualifying to help Paulo Bento's side qualify for the World Cup.