Spieth, a double major winner who stormed to a stunning wire-to-wire victory last year by four shots at the age of 21, will tee off at 9:48 a.m. ET (1348 GMT) with U.S. Amateur champion DeChambeau and Casey.
Australian world number one Jason Day, who landed his first major title at the 2015 PGA Championship, will launch his bid for a second consecutive grand slam crown in the company of American Matt Kuchar and South African Ernie Els.
Day, the hottest player in the game after winning six times in his last 13 starts, and company are scheduled to tee off at 1:06 p.m. on Thursday.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
In other groupings, 2013 champion Adam Scott of Australia will set off with Americans Kevin Kisner and Brooks Koepka while 2011 winner Charl Schwartzel of South Africa has been paired with American Davis Love III and Spaniard Rafael Cabrera-Bello.
Twice Masters champion Bubba Watson, aiming to become the sixth triple winner at Augusta National, will start out in the company of South African Branden Grace and Englishman Ian Poulter.
Northern Irish world number three Rory McIlroy, Germany's Martin Kaymer and American Bill Haas will tee off in the final group of the day on Thursday.
First off at 8:20 a.m., following ceremonial tee shots by golfing greats Jack Nicklaus and Gary Player, will be Australian Steven Bowditch and American Jim Herman, who earned a late spot at the Masters by winning the Houston Open on Sunday.
(Editing by Frank Pingue)
