Roger Federer has sat out training with his Switzerland teammates ahead of this weekend's Davis Cup final against France.
The 33-year-old is currently struggling with the back problem that forced him to withdraw from Sunday's final at the ATP World Tour Finals.
Federer has yet to train with the Switzerland team since arriving in Lille on Monday.
"I'm making some progress, but I know I don't have a month ahead of me to get better, I need to get better quickly," he is quoted as saying by Sky Sports News. "I'm trying whatever I can."
While Federer has won 17 Grand Slam title during his illustrious career, he has never been part of a successful Davis Cup team.
