Published: Nov 02, 2011 10:37 PM EDT
Updated: Nov 03, 2011 6:30 AM EDT

SHANGHAI (AP) - Rory McIlroy felt he was ready for a fresh start when he decided to leave longtime agent Chubby Chandler, a decision he said Wednesday was the most difficult of his career.

In the midst of a breakthrough season, and just four months after his record-setting win in the U.S. Open, the 22-year-old McIlroy surprised those around him last month by announcing he was leaving Chandler for Horizon Sports Management, a Dublin-based agency that also manages good friend and fellow U.S. Open champion Graeme McDowell.

The decision was a shock to Chandler, who never had an inkling his star client wanted to leave International Sports Management.

Those searching for answers didn't get many from McIlroy on the eve of the HSBC Champions. He repeated that he was interested in a "fresh view on things."