Jordan Spieth made a low-key start in his bid to win his final tournament before next week’s Open, as he shot an even-par 71 at the John Deere Classis in Illinois.
The 21-year-old will go for his third straight major when he tees up at St Andrews after stunning victories at the Masters and the US Open earlier this year.
At a venue where he won his first senior title two years ago as a teenager, he appeared to have the perfect platform to build on ahead of his trip to Scotland.
Yet he finished eight shots behind leaders Justin Thomas and Nicholas Thompson and is in danger of missing the cut, after a frustrating round which included three bogeys and a string of missed birdie opportunities.
"Just a little rusty," the world No 2 told reporters. "My first round of 18 holes since the U.S. Open was yesterday, and you know, I certainly saw a lot of rust and this was actually a slight improvement..
"I'm just looking to get a little better each day and I'm going to have to do a little better in order to play the weekend. A little disappointing, but at the same time, you know, I didn't put in the same preparation."
Spieth will take heart to an extent from the fact he was six behind after 18 holes before he went on to beat Zach Johnson and David Hearn in a play-off in 2013.
But he is clearly some way from peaking ahead of a tournament when he will be seen by many as the favourite after reigning champion Rory McIlroy’s withdrawal because of an ankle injury.
At the top of the leaderboard, Thomas carded 10 birdies, including four in his last five holes, to post a first round 63 and hold a share of the lead with Thompson, whose round included seven birdies and an eagle at the par-four 14th.
"I'm very pleased, it was nice to see some putts go in," Thomas told Sky Sports 4. "I hit it pretty well and the average shots that you usually get away with pars on I seemed to miss in good spots and take advantage of.
"The bogey I made at 13 was terrible but I just stayed positive, as the thing is about course is that you can make so many birdies that you don't need to get down about a bogey."
The American pair sit one stroke ahead of two other players from the USA, Charles Howell III and Luke Guthrie, with five more players on six under including three-time event winner Steve Stricker.
Defending champion Brian Harman, who beat Johnson to the title by a stroke 12 months ago, hit a 67 and is tied for 21st.
Watch the second round of the John Deere Classic live from 9pm tonight via the red button on Sky Sports 4 - your home of golf.