"The one thing I learned from my 10 years as Tiger's coach, and since then, is never say never when it comes to Tiger Woods", Harmon wrote.
"Right now it's easy to think he can be Tiger Woods again and be the best in the world, but that would be a stretch for him", Harmon wrote.
Rickie Fowler closed with a blistering 61 to finish at 18-under 270 for the weekend to claim the Hero World Challenge title.
The ever secretive Woods has revealed few specifics of his back operations or his rehabilitation, but his most recent spinal fusion surgery seems to have been successful, judging by his movement and swing patterns.
The 14-time major champion lit up the front nine at the Albany Golf Course, hitting the turn in 31 for the second time this week before having to settle for a four-under 68 to finish in a share of ninth on eight under. "I really drove the ball a lot better than I was thinking, especially distance-wise". ". I hit just a boatload of good putts".
Fowler sprinkled 11 birdies - including seven straight from Nos. Two takeaways from this 18-man exhibition in The Bahamas: the 41-year-old, who turns 42 on December 30th, completed four rounds for the first time since here last year - where he finished 15th on 4-under 284 (73-65-70-76) - and, he did so pain-free.
He finished equal ninth out of 18 competitors on Sunday, 10 shots behind victor Rickie Fowler, his best result in four years and certainly most respectable for a man who had not played a competitive round for 10 months.
Tommy Fleetwood and Jordan Spieth finished in a tie for third place on 12 under. How am I going to get used to the adrenaline in my system, because it's the first time in a while.
"I'm excited", Woods said on Sunday. Woods beat current World No. 1 Dustin Johnson by eight shots.