Bayern Munich winger Franck Ribery has said he is facing a race against time to be fit for Saturday's visit to Borussia Dortmund.
Ribery suffered an ankle injury in Bayern's 7-0 Champions League victory over Shakthar Donetsk earlier this month.
The 31-year-old has struggled with injuries throughout the campaign, starting only nine Bundesliga games, and remains unsure whether he will return in time for the match at the Westfalenstadion.
"It's a bit of a pain," Ribery told Bayern's official website. "At the moment, I'm having treatment every day and I'm on the bike and the treadmill.
"My hope is that, once all the international players are back next week, I can get back out on the pitch and train with the team.
"But I can't yet say for certain whether I'll feature at Dortmund."
Speaking to Sport Bild Plus, he said he felt he had caused further problems by trying to return to training too quickly, adding: "To begin that early was a mistake."
Meanwhile, Bayern midfielder Javi Martinez has said he hopes he can return to action "as soon as possible."
The Spain international suffered an anterior cruciate ligament tear in the Supercup final against Dortmund ahead of the season.
But he said he was finally closing in on a return to action, explaining: "It's about days, maybe weeks. I will not rush it. The knee needs to be at 100 percent, otherwise the danger of a setback is too high."