Greats say don't write off Federer

WUHAN, Hubei province - Two legends of tennis expect the "Big Four" to wage a battle royal for the Grand Slam crowns this season.

Pete Sampras and Carlos Moya may have retired from the pro tour, but they still keep a keen eye on the ATP circuit.

And, neither feels 16-time Grand Slam winner Roger Federer's best days are behind him.