Rory McIlroy admits he didn't feel comfortable playing his first round at Hilton Head in eleven years.
The world number 1 carded two birdies in his final five holes to complete a 1-over par round of 72 at the RBC Heritage.
McIlroy last played the tournament in 2009, and his lack of familiarity with his surroundings was evident on his front nine.
Bogeys at 11, 15 and 18 saw him make the turn in 3-over par.
"I'm missing my three-wood left and missing my driver right", McIlroy said after his wayward opening round.
"I got a little better towards the end and hit some decent tee shots.
"If you're in two minds about what to do off the tees around here and get a little bit sort of guidey, it can bite you.
"So I didn't get it in play enough to give myself shots or looks at hitting it close into greens and making birdies.
"It was just a little bit of a struggle, so I'm going to work on it a little bit this afternoon and see if I can straighten it out."
McIlroy's struggles were in stark contrast to his frequent Ryder Cup teammate Ian Poulter who shot a flawless round of 64 to enter the clubhouse on 7-under par.
Poulter was later joined on that mark by American Mark Hubbard.
Jordan Spieth rallied late in his round, producing seven birdies in his final eight holes to end the day well placed on 5-under par.
"I wasn't particularly comfortable out there," McIlroy said after his struggles.
"I played here once before in '09, and I just can remember not being that comfortable around here then, and it's still sort of the same.
"I'm just not comfortable and sort of trying to pick lines and really commit to shots. I just wasn't as committed today as I need to be around here.
"There are a few holes, obviously, that are familiar, a few on the front side, obviously a few coming in as well. But there are a lot of holes around the turn that I didn't really remember too well.
"I played a couple of practice rounds just trying to get lines off tees and get adjusted and feel comfortable with the clubs that you're hitting.
"Then again, it's a course that, once you do get it in play, you can give yourself plenty of chances."