Jordan Spieth was at a loss to explain what went wrong at his final hole as the world number two ended the opening round nine shots off the pace at The Players Championship.
Playing for the first time since his stunning collapse at last month's Masters as Danny Willett captured the green jacket, Spieth double-bogeyed the ninth hole for an even-par 72 in Ponte Vedra Beach, Florida on Thursday.
Spieth, who started on the back nine at the challenging TPC Sawgrass, had only dropped one shot prior to the turn but the American came unstuck late, with back-to-back bogeys at the fifth and sixth holes followed by a double-bogey at the par-five ninth to close out the round well adrift of leader Jason Day.
Speaking after his final-hole collapse, Spieth said: "I hit it seven times.
"I hit two fantastic shots, and then not really sure after that.
"I really only had two bad swings today. I'm hitting the ball great, which is what I've been working on the past couple weeks, trying to get more consistent and better ball-striking, better control of it."
Spieth added: "I feel as comfortable over the ball and driving it the best I've driven it the whole year, hitting it great, just distance control and then my speed control with the putter, which are things that sometimes take a round or two to get back.''