Didier Drogba has been ruled out of Chelsea's trip to Sporting Lisbon in the Champions League with an ankle injury.

The veteran striker has been struggling with the problem for the past two weeks.

Despite playing in his side's win over Bolton Wanderers in the League Cup last week, Drogba has not travelled with his teammates to Portugal.

"Seems I came back too quickly from my ankle injury & have aggravated it further in training so won't be travelling with team today....," he tweeted.

Chelsea face Sporting in Group G of the Champions League on Tuesday night.