Jason Day says he decided to replace long-time caddie Colin Swatton because he was worried the relationship would become “toxic”.

Swatton, who has been on Day’s bag since he turned professional in 2006, was relieved of his duties ahead of the BMW Championship, with childhood friend Luke Reardon taking the Australian’s bag at Conway Farms.

Day, who had his major breakthrough at the 2015 PGA Championship and spent 51 weeks at world No. 1 with Swatton on the bag, said his now former caddie was “shocked and disappointed” at the news.

“He needed some time just going over things and really understand my feelings and what I wanted to try to accomplish in my career as a player, and then obviously trying to get his feelings as well,” Day explained.

“It’s always hard because we’ve been a team for so long. We’ve been really tight and being so close for very long and we’re still close.

“I never wanted it to turn into a toxic relationship where he’s taken me from where I am as a 12-year-old kid to where I am today and I’m not talking to him anymore.”

Swatton will remain Day’s swing coach – a position he has held since Day was 12.

“He’s always going to be my coach, always will, unless he gets paid more somewhere else,” Day added.

“I’m planning on trying to keep him around. I don’t want anyone else to get coached by him because he’s a really good coach.”

While Day considers Reardon, pictured by a fan at Conway Farms on Wednesday, as a long-term solution, he has also not ruled out a return for Swatton on the bag.

He said: “It may be somewhere down the road I can come back to him and say, ‘Look, man, I made a mistake and I need to come back and have you on the bag.’

“[We] have been inseparable since the day I came out. I love him so much. I just want to make sure I did the right thing. Obviously, when you let go of someone sometimes it’s hard, but there’s been a lot going this year.”

It’s the third high-profile player-caddie split of the summer. In June, Phil Mickelson and Jim ‘Bones’ Mackay went their separate ways after 25 years, while Rory McIlroy sacked JP Fitzgerald just shy of a decade together.

Mickelson hired brother Tim, while McIlroy has close friend Harry Diamond on the bag. But Day said it had no bearing on his decision.

“I’m comfortable around Col just as my mate. There’s no correlation between what [Mickelson] did to go to his brother and Rory going to his best mate.

Day is currently 28th in the FedEx Cup standings and must still be inside the top 30 on Sunday to advance to the season-ending Tour Championship.

With Reardon’s visa up at the end of September, he will be able to caddie for Day at the BMW Championship and the Tour Championship, should he qualify, but not the Presidents Cup.

“There’s no thinking there, I can severely underpay him,” Day joked.