Committed: To caddie for Justin Thomas this week in the Sony Open in Hawaii, Jim “Bones” Mackay. The veteran looper, who spent 25 years with Phil Mickelson until late last spring, has been working as an on-course reporter for NBC and Golf Channel. Jimmy Johnson, Thomas’ regular caddie, has struggled with plantar fasciitis in recent months. He caddied for Thomas for the first two rounds at the Sentry Tournament of Champions at Kapalua (Hawaii) Resort’s hilly Plantation Course before calling off for the weekend. Thomas, the reigning PGA Tour player of the year and a five-time winner last season, summoned his father, Mike, a PGA professional, to the bag for the final two rounds at Kapalua but could finish only T-22 in the 34-man winners-only field.