The Swiss fell by a double 7-5 in an hour and 40 minutes against Thiem and his presence is complicated in the semifinals of the ATP Finals.
"I think he played very well. My start of the game did not help, then I recovered well and it matched for a long time. I had my chances and got into trouble in the service. He got very good as he had to do. My game has not been good enough, "he said.
Federer said that the public is not unfair to support him more than his rivals in the matches and said he wish he had given them something to celebrate.
In the face of the confrontation with Matteo Berrettini, in which his options to move to the semifinals will be played, Federer said he has to recover and be sure that he plays better than this Sunday.
After the meeting of Berrettini and in case of continuing in the tournament, Federer will have to see the faces with Novak Djokovic, who this Sunday could with the Italian. EFE