Fox, of Auckland, pulled out of the unofficial fifth major in Florida just before the opening round due to illness.
The 39-year-old has since revealed that he is in hospital after suffering from kidney stones.
"Not exactly the week I had planned here," Fox posted on Instagram.
"Unfortunately some kidney stones took me down on Tuesday night and then had to be dealt with surgically this afternoon.
"Devastated to miss out on such an amazing event, hoping to have a quick recovery and be back at it soon."
He was replaced in the 123-man field by David Ford, who will be among 15 players competing for the first time at the TPC Sawgrass.
Fox has been in good form so far this year, finishing in the the top 25 in all four events played and has pocketed $1.7 million.
He won the Myrtle Beach Classic and the Canadian Open last year and is No 44 in world rankings.
The Players Championship is worth $43 million with the winner taking home $7.7 million.
Fox's best result at the tourament was last year when he finished tied for 20th.
American Colin Morikawa also withdrew from this year's tournament with a back injury, but world No 2 Rory McIlroy, of Northern Ireland, is playing after recovering also from a back injury.
