Roger Federer opens up about his lack of concentration.

Jim Courier announced his U.S. Davis Cup roster for tie against Chile.

Andy Roddick and Lleyton Hewitt renew their rivalry tonight in Memphis.

Andy Roddick survived a good test from Richard Berankis in Memphis last night.

Andy Roddick could be in for a battle tonight against 20-year-old Richard Berankis.

Slumping Sam Querrey loses another, Del Potro picks up a win and Murray returns.

The few number of overall American men in the draw took a further hit when vaunted comer Ryan Harrison unceremoniously exited to unheralded Frenchman Adrian Mannarino in straight sets.

Two players on the sidelines are trying to figure out how to tweak their games in time for the Australian Open — both dealing with equipment issues. Maria Sharapova switched from her long-time Prince racquet to a multi-million sponsorship with HEAD, but last week lost early in her only WTA warm-up event. This week world No. 1 Caroline Wozniacki debuted her cash-grab switch to Yonex, losing her opening-round match. Wozniacki vaulted to No. 1 behind her long-time association with her Babolat racquet. Before the event, Wozniacki and her Yonex won one game off Vera Zvonareva in an exhibition match.

Notes: (8) Lu opens against Simon, and (6) Lopez vs. (WC) Del Potro; other wildcards to Brit James Ward and Aussie Matthew Ebden; Baghdatis beat Gasquet in last year’s final; Del Potro makes his first tournament appearance since October and only his third in the last 11 months after a right wrist injury that required surgery; American Donald Young lost in the qualifying as did Aussie Carsten Ball; seeds Querrey, Gulbis and Lopez have losing career records in Sydney; the Bryan brothers, winners in 2009, are the top seeds in the doubles; Baghdatis, the only returning champ in the field, is looking to become the first back-to-back winner since James Blake (2007-06); Pete Sampras and Lleyton Hewitt (twice) won back-to-back titles, but no one has one three in a row in Sydney in the Open Era.

Sean Randall previews the 2011 ATP season.