World Cup: Cristiano Ronaldo reportedly suffering from chronic leg injury

Reigning FIFA player of the year Cristiano Ronaldo figures to play a big part in the World Cup for Portugal this summer, but injuries could mute his impact in Brazil.

The Real Madrid star, hobbled in the latter parts of the 2013-14 club season due to a series of injuries, has reportedly been diagnosed with knee tendinosis in his left leg.

ESPN tweeted out the report on Wednesday morning regarding the Portuguese star's health:

Ronaldo and Portugal are currently in the United States, where they will take on Mexico in a World Cup tune-up on Friday at Gillette Stadium (8:30 pm ET, ESPN2/UniMas). Ronaldo sat out Portugal's last friendly, a scoreless draw against Greece in Lisbon last Saturday.

According to a report from EuroSport, the 2013 Ballon d'Or winner has been in "specially adapted, individual" training this week as a result of his injuries, which also reportedly includes a left thigh ailment.

After the Mexico friendly, Portugal are set to face the Republic of Ireland in their final preparation match on June 10 at MetLife Stadium in East Rutherford, New Jersey, before going to Brazil. They open Group G play June 16 in Salvador against Germany, and will take on the US national team June 22 in Manaus.