The 23-year-old Spaniard was injured Tuesday in a kicking competition at Perth, where he was one of six golfers who joined six players from the Australian Football League.
Garcia withdrew from a pro-am tournament Wednesday, the day before the Johnnie Walker Classic starts at the Lake Karrinyup Country Club.
'We're guessing it was kicking the football yesterday, but it never hurt when I was doing it,' Garcia said Wednesday. 'I didn't feel a twinge or anything like that.'
The world No. 6, who was third at the Johnnie Walker Classic last year, said he was going to monitor the injury overnight.
'I'm going to keep treating it and I will go and hit some balls as well and we will see how I feel,' he said. 'Whatever happens, I won't make any decision about playing until tomorrow.'
Retief Goosen won the Johnnie Walker Classic by eight strokes last year, but is expected to get heavy competition by fellow South African Ernie Els, the world No. 2 who has won four of his last five tournaments.
Els had a week off after overcoming a 10-stroke deficit in the last two rounds to win the Heineken Classic in Melbourne two weeks ago.
The tournament is jointly sanctioned by the European, Asian and Australasian PGA tours.