Suspension 'sharpened' Sharapova

LOS ANGELES - Five-time Grand Slam champion Maria Sharapova says her 15-month doping ban has only sharpened her passion for tennis.

The former world No 1 from Russia, preparing to play at Stanford next week in her first WTA tournament in the United States since her suspension ended, wrote on the Players' Tribune website of the roller-coaster of emotions she has experienced since returning to competition in April.

"Though these last two years have been tougher - so much tougher - than I ever could have anticipated ... my passion for the game never wavered," Sharapova wrote. "If anything, it's only grown sharper."