By Nick Georgandis

Thomas Hogstedt knows a thing or two about returning former No. 1 players to the top spot in the world. Caroline Wozniacki is hoping he can do for her what he did for Maria Sharapova.

Wozniacki announced she had hired the Swedish Hogstedt as her new coach, replacing her father Piotr, who was quoted last week as saying the WTA Championships would be his last tournament as her primary coach. Hogstedt, who coached Li Na for a time, was also being pursued by the UK's Laura Robson.

Wozniacki is one of three female players to have achieved the No. 1 ranking without winning a Grand Slam title - a feat she first accomplished on Oct. 11, 2010, when she overtook an injured Serena Williams.

She has been No. 1 for 67 weeks in her career, the ninth-most in Open Era history, but has since fallen back to the bottom half of the Top 10. She went just 39-22 in 2013, the fewest wins of her career since 2007, when she was ranked 64th in the world.