The 33-year-old tested out his back on the clay in Lille, France on Wednesday ahead of this weekend's Davis Cup final.
Eight men with success on the challenger tour this season will compete in Sao Paulo, Brazil in the round robin event.
The model and actress reveals in a new book when Agassi first told her about his drug addiction.
Telegraph correspondent Simon Briggs has unearthed video of Mirka Federer calling Stan Wawrinka a "cry baby" in London last Saturday.
The 17-year-old Swiss rose nearly 200 spots in the rankings to finish 2014 at 32 in the world.
How's this for brotherly love? Mike Bryan takes a serve to the head in the London final, and lives to tell.
Are Roger Federer and Stan Wawrinka feuding before the Davis Cup final?