Rory McIlroy has been drawn with Tiger Woods and Adam Scott as the world's top three play the opening two rounds of the US Open at Merion together.
McIlroy, 2011 champion and world number two, plays alongside world number one Woods and Masters champion Scott.
Northern Ireland's Graeme McDowell, the 2010 champion, is grouped with Americans Jim Furyk and Zach Johnson.
Englishmen Luke Donald and Lee Westwood will play with 2012 Ryder Cup team-mate Martin Kaymer.
Defending champion Webb Simpson and Open winner Ernie Els are in a trio with 2012 US Amateur champion Steven Fox.
Woods and Sergio Garcia are in the same tournament for the first time since their spat at The Players Championship in May, which was followed by Garcia having to apologise for a remark he made about the American.
Spaniard Garcia will tee off when the event gets underway on Thursday with former Open champions Padraig Harrington and Stewart Cink.
The field will be finalised after the Lyoness Open on the European Tour and FedEx St Jude Classic on the PGA Tour finish on Sunday, with the world's top 60 set to take part in the second major of the year.