While 40 of the world’s top 50 players are contesting the WGC-HSBC Champions event in Shanghai, world number 340 Harrington is one of nine former major champions in the field at Jackson Country Club.
Harrington, who reached third in the world six months after winning his third Major title in the 2008 US PGA Championship, will partner fellow major winners Lucas Glover and David Toms in the opening two rounds of the $4 million (€3.2m) event.
Glover has also plummeted down the rankings since winning the US Open in 2009 and is now a lowly 556th, while 2001 US PGA champion Toms is ranked 173rd.
John Daly, YE Yang, Trevor Immelman, Ben Curtis, Chad Campbell and David Duval are the other major winners in the field, which also features rising Australian star Cameron Smith.
Smith finished tied fifth on his PGA Tour debut in the CIMB Classic in Malaysia last week to secure his place, the 21-year-old becoming the first player since Alistair Presnell (2010 WGC-Cadillac Championship) to finish in the top 10 in his first PGA Tour start.