Bayern Munich coach Jupp Heynckes says Arjen Robben will be out of action for longer than expected, with the Dutch winger ruled out for ''some weeks.''

Heynckes told the club's online TV channel Thursday that Robben ''needs 14 days rest before starting with light rehab and running training. You can't put an exact date on it at the moment.''

The 27-year-old Robben, who underwent an operation on a long-standing groin injury last Friday, has been beset by back and groin problems this season.

Robben has completed only one league game so far.

Heynckes said, ''When he's back and fit again you can forget the whole discussion. Then Bayern will be even better.''

Bayern leads the Bundesliga but has a run of seven games in 23 days coming up.