Clarke will announce his three selections at Wentworth on Tuesday ahead of trip to Chaska, Minnesota.
Federer and Nadal have won 31 Grand Slam titles between them.
Stenson, McIlroy and Willett lead the European Points list
East Lothian course was barred from hosting The Open after May ballot saw continued ban on women members.
The Northern Irish captain did admit he was surprised by the result of the 23 June vote.
Golf's biggest team event will take place at Marco Simone course outside Rome.
Davis Love III adds three names to his five-man backroom team for match at Hazeltine in 2016.
Exclusive: The 44-year-old believes a good start to the New Year will keep him in the running for all three.
The Spaniard says his game was not up to what he had done this year.
Jamie Donaldson sealed the victory on the 15th hole for Paul McGinley's side.
Live coverage of the final day of the Ryder Cup as Europe aim to defend their title.
Paul McGinley's side secured a 3½-½ win in the afternoon's foursome sessions.
Paul McGinley's side lead trail 6½-5½ after the morning session.
Justin Rose and Henrik Stenson win two points in Friday's fourballs and foursomes at Gleneagles.
Phil Mickelson and Keegan Bradley beat Rory McIlroy and Sergio Garcia to secure crucial point.
Information and times for the opening fourballs Friday morning and foursomes in the afternoon.
The first morning fourballs will begin Friday morning at Gleneagles.
Ukip leader and staunch anti-federalist Nigel Farage backs Europe for Ryder Cup glory.
Preview the Ryder Cup opening ceremony which includes confirmation of opening fourballs.
Manchester United great left world number one Rory McIlroy 'in a trance'.
European vice-captain believes a mental block could affect Tom Watson's side.
Northern Irish pair's relationship not affected by Horizon legal battle says McDowell.