Cristiano Ronaldo was one of 10 Real Madrid players subjected to anti-doping tests this week.
According to Madrid-based Marca, anti-doping officials from UEFA paid a surprise visit to Real Madrid's training ground to carry out tests.
And Ronaldo, who is favourite to claim his second consecutive Ballon d'Or trophy in January, was one of the 10 players selected.
It is the second time this season that Real have been targeted after members of the squad underwent similar tests before the European Super Cup final against Sevilla in Cardiff in August.
Earlier this week Lionel Messi was asked to give a blood and urine sample during Barcelona anti-doping tests after the Argentine scored his third hat-trick in four games against Espanyol last weekend.
Five Barcelona players were chosen for testing, but only Messi was asked to provide both blood and urine, something the 27-year-old found 'weird'.
Ronaldo has been in scintillating form for Real this season, scoring an incredible 32 goals in just 24 appearances in all competitions.
The Portugal international will be looking to keep up his goalscoring exploits against Almeria on Friday as Real look to extend their winning streak to 20 matches.
Source: Dailymail football