Justin Thomas parts with caddie 'Bones' Mackay

Justin Thomas and Jim "Bones" Mackay are going their separate ways about a week before The Masters.

The former World No. 1 had partnered with Mackay full time since September 2021. "Bones" first worked with Thomas in January 2018, when he took a one-week break from broadcasting to fill in for the injured Jimmy Johnson.

Mackay, who turns 59 on May 8, helped Thomas win the PGA Championship in 2022, the second major title of the 30-year-old's career. Thomas overcame a tournament record seven-shot deficit entering the final round.

Mackay worked as Phil Mickelson's caddy for 25 years, from the start of Lefty's career in 1992 until 2017. After Mickelson, he joined NBC and Golf Channel as a commentator.

He also worked with Larry Mize, Curtis Strange, and Scott Simpson before teaming up with Mickelson.

Thomas got off to a strong start this season, tying for third at The American Express and sixth at the Pebble Beach Pro-Am. He finished T12 at the WM Phoenix Open in February but missed the cut at two of his next three events.

The Kentuckian tied for 64th at the Valspar Championship in late March.