Golf’s caddie merry-go-round continued when former world number one Jason Day revealed on that he has sacked long-time bagman Col Swatton.

Swatton has been a father-figure for Day, doubling as caddie and coach -- a role he will maintain -- for the 29-year-old Australian's entire career.

Day acknowledged that Swatton had been a bit shocked at the news but said he had taken it like a professional.

"Unfortunately it just didn’t work out," Day said on the eve of the BMW Championship at Conway Farms, outside Chicago.

"I’m trying to find my footing here. I had to do it at some point."

Day was clearly the best player in the world for the second half of 2015 and the first part of 2016, clinching his first major at the PGA Championship, but has struggled in relative terms lately, slipping to his current ranking of ninth.

Day, who plans to use a friend, Luke Reardon, on the bag this week, said he planned to keep Swatton as his coach.

"He’s just coming off the bag and going to more of a coaching role," Day said.

"He’s not out of my world one bit. I’m hoping things move forward with us like they always have because we both love each other like family."

Day was a 12-years-old when he met Swatton at an Australian golf academy, and Day has often said he would not be where he is without his mentor.

Swatton even played matchmaker by introducing Day to his now-wife, Ellie.

The news comes a month after another former world number one, Rory McIlroy, dumped his caddie, JP Fitzgerald.

In June, five-times major champion Phil Mickelson parted with Jim Mackay after 25 years.