Portugal 1-1 Serbia: Cristiano Ronaldo suffers hamstring injury

Portugal drew 0-0 with Ukraine in their opening European Championship qualifier on Friday

Forward Cristiano Ronaldo went off injured as Portugal drew their European Championship qualifier against Serbia.

Ronaldo was substituted after appearing to injure a hamstring after 31 minutes.

Serbia led at the time after Dusan Tadic's early penalty but the hosts equalised through a spectacular 25-yard strike from Danilo Pereira.

"I'll know more in 24 or 48 hours," said Ronaldo. "It happens. If you go out in the rain you get wet. I'm calm, I'll be back in one or two weeks."

His club, Juventus, are 15 points clear at the top of Italy's Serie A and face Ajax in the Champions League quarter-finals.

The first leg takes place in Amsterdam on 10 April, with the return leg in Turin on 16 April.

Euro 2016 winners Portugal have begun their defence with two draws at home in their qualifying group after being held to a scoreless draw by Ukraine on Friday.

Portugal thought they had a penalty when the referee pointed to the spot after the ball hit the outstretched arm of Antonio Rukavina from Andre Silva's close-range header.

However, after conferring with an assistant, the official reversed his decision.

The hosts were lucky to finish the game with 11 men after Pepe, who was booked in the first half, caught Tadic on the ankle in the 57th minute, but he escaped further punishment.