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

A significant change for one of the PGA Tour's biggest stars comes just before the season's first major

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 had 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.

Mackay will be an on-course reporter for NBC's coverage of the Augusta National Women's Amateur event this weekend, a previously announced commitment. NBC did not comment on Mackay's future to Yahoo Sports beyond that point.

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. Golf Channel's Todd Lewis indicated that Matt Minister, who caddied for Patrick Cantlay when Cantlay won the 2021 Tour Championship, will be on the bag for Thomas in Augusta.