( CNN ) -- Swiss star Roger Federer faces a race against time to be fit for the Davis Cup final against France . The 33-year-old Federer pulled out of the final of World Tour Finals against Novak Djokovic Sunday due to a back injury , raising doubts over his participation in the showpiece match that starts in Lille on Friday . `` We will have to see how severe those back problems are and we hope that Roger will be able to recover until next Friday , '' the Swiss Davis Cup captain Severin Luthi said in a statement on Facebook , referring to the final that is being staged November 21-23 . `` He now has to rest , '' added Luthi . `` Our team doctor Roland Biedert has come to London and , together with our physiotherapist Daniel Troxler , will work on Roger 's fast recovery . '' But speaking at a news conference on Tuesday , Federer sounded cautiously optimistic . `` My back is better than it was Sunday , but not good enough for practice yet . But I 'm hopeful , '' he said . After pulling out of Sunday 's final against Djokovic , Federer adopted a more optimistic tone than Luthi . `` This back spasm [ or ] whatever it might be , it 's just not a fun thing to have during the day , '' Federer said on the official Davis Cup website . `` It 's just uncomfortable . But I 'm positive and I 'm hopeful that it 's going to go away very soon . '' Federer was plagued by back issues in 2013 , largely contributing to a subpar campaign -- by his illustrious standards . He has enjoyed good health in 2014 , though , one of the reasons the 17-time grand slam champion was able to No . 2 in the world rankings . The Swiss star picked up the injury in the third-set tiebreaker of his late-night 4-6 7-5 7-6 ( 6 ) victory over Davis Cup teammate Stan Wawrinka Saturday . Wawrinka crunched a backhand at Federer when the latter was at the net and also , at one stage , Wawrinka jawed at the Federer camp , seemingly unhappy with something that was said to him . The Davis Cup title , along with an Olympic singles gold medal , is one of the few gaps in Federer 's resume .
Roger Federer faces fitness battle to be ready for Davis Cup final . Said he was n't `` match fit '' for final of World Tour finals against Novak Djokovic . Federer had played for about three hours Friday in beating fellow Swiss Stan Wawrinka . Roger Federer final between France and France starts Saturday in Switzerland .