Phil Mickelson and former caddie Jim "Bones" Mackay will be reunited tomorrow for the first time in three years during the final round of the WGC-FedEx St. Jude Classic.

But it won't be like old times.

Mickelson shot 66 on Saturday to play himself into the third-last pairing alongside Justin Thomas, who has Mackay on the bag this week after his regular looper, Jimmy Johnson, was forced to stay home to deal with dizziness issues.

Mackay last caddied for Mickelson at the 2017 St. Jude Classic in Memphis before leaving to work as a broadcaster for NBC. He occasionally caddies for PGA Tour players in need, most recently for Matt Fitzpatrick at Muirfield Village two weeks ago.

Thomas and Mickelson - and "Bones" - tee off at 2:45 p.m. ET, trailing leader Brendon Todd by four and five shots, respectively.