Bayern Munich boss Matthias Sammer has told Franck Ribery he needs to be more patient as the French winger's persistent ankle injury refuses to heal.

The 32-year-old has not played since limping out of a Champions League match in March with an injury to his right ankle.

Ribery has described the situation as a "catastrophe" with no date set for his return despite constant treatment, while new-signing Douglas Costa of Brazil has become a shoo-in on Bayern's left wing in his absence.

Bayern's director of sport Sammer said they are fully behind helping Ribery regain his fitness, but said the Frenchman must be patient.

"Franck is happy when he is on the pitch and when he can play football, so in this respect he is definitely unhappy at the moment," Sammer told German daily Bild.

"But he is doing everything he can to make a comeback.

"Our task is to help him with our strength and with all the means at our disposal, but we have to be patient."

Ex-Bayern captain Stefan Effenberg has said he has doubts Ribery will make a comeback while Sammer says they have consulted a wide range of international experts.