Rory McIlroy has fired his caddie and will use his best friend at the Bridgestone Invitational and PGA Championship, according to published reports.

Reuters cited a source it did not identify as saying McIlroy has parted ways with J.P. Fitzgerald. They have worked together for the past nine years, during which McIlroy has won four major championships and reached No. 1 in the world.

McIlroy is due to speak about the change Wednesday at the Bridgestone Invitational.

The Telegraph reported that McIlroy's caddie at the next two tournaments will be Harry Diamond.

It is the second significant player-caddie split this summer. Phil Mickelson and Jim "Bones" Mackay decided to end 25 years together. Mackay since has taken a job as an analyst on the course at NBC Sports.