The US Open was suspended on the opening day of the tournament due to thunderstorms, with just nine players able to complete the first round at Oakmont Country Club.
American Andrew Landry currently sits at the top of the leaderboard after shooting three-under-par through 17 holes, while Bubba Watson sits one shot off the pace after playing 14 holes.
Englishman Lee Westwood put himself in contention on Thursday as he is one-under-par through 13, but he suffered some trouble on the front nine as he shot two bogeys on the first and second holes.
Two birdies and an eagle on the 14th pushed Westwood up the leaderboard, but it was a different story for Rory McIlroy as the 2011 champion hit five bogeys and just the one birdie through 13 holes.
The Northern Irishman is four-over-par, while defending champion Jordan Spieth is one-over through 11 after two bogeys and a birdie.
Spieth and his playing partners Bryson DeChambeau and Zach Johnson were warned by a rules official to speed up their play after leaving the 16th tee.
