The Swiss legend won a gold in doubles in Beijing in 2008, but has never been on the top of the medals podium in singles despite lingering frustration at knowing he should have been involved at least once.

"It's different pressure because the form is best of three so you feel like you have a bad five minutes and that could be it. That's kind of what cost me against (Tomas) Berdych in Athens, against (James) Blake in Beijing," said Federer.