BMW Championship officials were waiting on the weather on Monday to see if the event could be completed, with 54-hole leader Justin Rose on the brink of victory.
After rain wiped out Sunday's play in Philadelphia, the final round was pushed back to Monday, with the PGA hopeful the FedEx Cup Playoff event would be able to resume.
But should the weather again prove disruptive, at least half the field would have to complete their round in order to take the tournament into a sixth day on Tuesday.
If that is not possible, the event will be called off after 54 holes, giving Rose victory and seeing the projected top 30 in the FedEx Cup standings progress to the Tour Championship.
Three-time major champion Jordan Spieth is among those that would currently miss that cut, projected 31st after the third round.
"We will do everything we can to play [on Monday]," said Slugger White, PGA Tour vice president of rules and competition. "We'll just see what Mother Nature gives us.
"If we get in and we get half the round completed, yes, we would be into Tuesday. If we don't ... it's really too early to talk about that."
Rose leads by one stroke from Rory McIlroy, while the pair's European Ryder Cup team-mates Tyrrell Hatton, Alex Noren, Ian Poulter and Henrik Stenson are among those outside the projected top 30.
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