The HP Byron Nelson Championship will be played May 17-23 at the TPC Four Seasons Resort Las Colinas in Irving, Texas. Rory Sabbatini, the defending champion, also has committed to play.
Cink, who was six career PGA Tour victories, currently is No. 29 in the World Golf Rankings. He has played 11 events this season, with his best finish coming at the WGC Accenture Match Play Championship, where he finished fifth. He is 56th on the PGA Tour money list.
Singh, 46th on the world rankings and 87th on the Tour money list, has one top-10 this season, finishing fourth at The Honda Classic. He is a former champion at the Nelson, winning in 2003 as part of his 34 career Tour victories.
Immelman, who finished 14th at the Masters earlier this year, was runner-up at the Nelson in 2006. He ranks 135th on the Tour money list.