Madrid, Sep 16 (IANS): Forward Gareth Bale suffered a worrying calf injury as Real Madrid opened their Champions League account with a 4-0 win over Shakhtar Donetsk.

Bale limped off the pitch with a calf injury moments after Karim Benzema had opened the scoring with a tap in following a dreadful error by the Shahktar goalkeeper, who dropped a simple cross at his feet on Tuesday night, reports Xinhua.

The loss of the Welshman, who has been in fine form in early season, is a major worry for Real Madrid and also for Wales, who need just one point to qualify for next summer's European Championships.

Following Tuesday's game Real Madrid coach, Rafael Benitez admitted he was worried and that the club would have to wait before they discovered the full extent of the injury.

"Bale has had a spasm in his calf," said Benitez in his post-match press conference on Tuesday, before adding the club would have to wait, "a few days," discover just how serious the injury was.

Bale has been plagued by muscle problems during his career, which Benitez admitted was a worry for the club.

"He had a similar problem last year so we've got to be a bit more careful," said Benitez, who added that although defenders Sergio Ramos and Rafael Varene also had to leave the pitch before time, their problems were not serious.

"Gareth is the only one that is a bit more negative but we'll have to wait and talk with the doctors to see what happens," he concluded.

Whatever be the result of the tests, it seems Bale will miss at least two games; Real Madrid's La Liga home match against Granada and a more difficult trip to face Athletic Club Bilbao.