Published: Aug 31, 2011 12:42 PM EDT
Updated: Sep 01, 2011 6:30 AM EDT

CRANS-SUR-SIERRE, Switzerland (AP) - U.S. Open winner Rory McIlroy says his relationship with top-ranked tennis player Caroline Wozniacki can help him become No. 1.

McIlroy says he and Wozniacki "definitely spur each other on and it's very healthy."

The 22-year Northern Irishman says he's impressed with Wozniacki's dedication, and can learn from her work ethic after spending time with her at two tennis events in the United States.

He spoke ahead of the European Masters in Switzerland, his first tournament since injuring his right arm at the PGA Championship.

Wozniacki is playing in the U.S. Open in New York, seeking her first win at a Grand Slam tournament.