Roger Federer lost his No. 1 world ranking to Rafael Nadal following the French Open, and Federer would like it back, thank you very much. In order to do that, Federer has begun a trial training period with Paul Annacone, Pete Sampras' former full time coach from 1995-2001.
Federer announced the new development on his website in a letter to his fans:
Dear Fans
I've been looking to add someone to my team and I've decided to spend some days with Paul Annacone. As Paul winds down his responsibilities working for the Lawn Tennis Association, we will explore our relationship through this test period. Paul will work alongside my existing team and I am excited to learn from his experiences.
See you soon
Roger
Federer's streak of 23 consecutive Grand Slam semi-finals was snapped this year at the French Open in his quarterfinal loss to Robin Soderling of Sweden.
From Bloomberg:
Annacone will be leaving his job as head coach of the U.K.'s Lawn Tennis Association at the end of November after more than three years. Before his time with the LTA, the American coached 14-time major winner and former world No. 1 Sampras and Tim Henman, previously British No. 1.
[...]
Federer, holder of a record 16 Grand Slam titles, had been guided by Australian coaches Peter Carter, who died in 2002, and Tony Roche. Since splitting from Roche in 2007, the Swiss has worked with his nation's Davis Cup captain Severin Luthi.
Annacone is also currently Great Britain's Davis Cup team coach but he announced in May that he will step down in November.