The decision by the quartet not to play in the tour's flagship event comes as a big blow to the organisers.
Course redesigner Ernie Els has masterminded major alterations to Wentworth in recent years and the changes have not met with unanimous approval by the players.
It has never been a happy hunting ground for Stenson, Garcia or Poulter but Arizona-based Casey has good memories of the West Course layout on the outskirts of London.
Englishman Casey won the PGA Championship at Wentworth in 2009 and also lifted the World Match Play title at the same venue in 2006.
World number three Stenson has only managed two top-10 finishes since the Swede made his debut in the tour's flagship event in 2001 while 10th-ranked Garcia went 12 years between 2001-12 without playing in the competition.
European Ryder Cup talisman Poulter has become embroiled in a row on social media after making his feelings clear about the tournament on his Twitter account.
"I've played 13 PGA's at Wentworth and had 1 Top 10," the Englishman tweeted. "I've had 8 MC (missed cuts). Would (world record sprinter) Usain Bolt compete in a marathon? I didn't think so ... Enough said."
On the plus side for fans of the PGA Championship, world number one Rory McIlroy will be back to defend his title when the event gets underway on May 21.
World number nine Justin Rose and U.S. Ryder Cup player Patrick Reed are also among the leading players competing in the tournament that carries a prize fund of 5 million euros (£3.58 million).
(Editing by Justin Palmer)
Share
