Justin Thomas splits with caddie Bones Mackay on the eve of the Masters

One of golf's most notable player-caddie partnerships is no more. Justin Thomas announced Wednesday that he and Jim "Bones" Mackay have parted ways.

The duo have been partnered since late 2021, and won the 2022 PGA Championship together. Thomas made the announcement of the split on social media Wednesday afternoon.

“I’m going to be forever thankful for him joining me on the bag in 2021,” Thomas wrote. “His wisdom on and off the course has been a blessing during a tough stretch of my career and he was there every step of the way.”

Mackay was Phil Mickelson's longtime caddie before the duo split in 2017. Mackay then moved into the broadcasting game, doing work as an on-course reporter for NBC/Golf Channel for several years before joining up with Thomas. Earlier this season, Mackay did another analyst stint at NBC for the Mexico Open, though he insisted at the time that he was not interested in filling the position still open after Paul Azinger was not retained by the network.

Thomas has struggled to find his form after that 2022 PGA Championship victory. He missed last year's FedEx Cup playoffs, though he was still named to the U.S. Ryder Cup team. He'll be in the field for this year's Masters, with a new caddie, starting in Augusta next week.