Roger Federer faces fitness battle to be ready for Davis Cup final . After pulling out of Sunday 's final against Djokovic , Federer adopted a more optimistic tone than Luthi . Said he was n't ` ` ' fit '' for final of World Tour finals against Novak Djokovic . Federer had played for about 24 hours Saturday in against fellow Swiss Stan Wawrinka . Davis Cup final between Switzerland and France starts Friday in Lille .
Roger Federer faces fitness battle to be ready for Davis Cup final . Said he was n't ` ` ' fit '' for final of World Tour finals against Novak Djokovic . Federer had played for about 24 hours Saturday in against fellow Swiss Stan Wawrinka . Davis Cup final between Switzerland and France starts Friday in Lille .