Jordan Spieth will begin the defense of his U.S. Open title Thursday alongside Zach Johnson and Bryson DeChambeau at 8:35 a.m. ET in a traditional grouping of the reigning Open and U.S. Amateur champions.

The trio will play together during the first two rounds of the 116th U.S. Open at the Oakmont Country Club in Pennsylvania.

No. 1-ranked Jason Day will play with fellow Aussie Adam Scott and South Africa's Louis Oosthuizen beginning at 2:20 p.m.

Rory McIlroy, the third-ranked player in the world, tees off with Masters champion Danny Willett and Rickie Fowler at 8:24 a.m.

Other groupings will see Dustin Johnson -- who three-putted the final green a year ago to lose to Spieth by a shot at Chambers Bay -- along with Hideki Matsuyama and Sergio Garcia tee off at 1:36 p.m.; Phil Mickelson, Justin Rose and Henrik Stenson tee off at 2:09 p.m.

The 156-player field will become complete Sunday following the latest Official World Golf Ranking. Anyone who was not previously eligible and who is among the top 60 at that point will get into the field, and any other spots will be filled through alternates from sectional qualifying.

The field will be cut to the top 60 players and ties through 36 holes, with an 18-hole playoff scheduled for June 20 if there is a tie after 72 holes.