The Farmers Insurance Open will stretch into Monday after fog wrecked the third day's play at Torrey Pines.
Only half a dozen players made it out on to the course to start their third rounds due to the conditions.
Tiger Woods did not get out of the clubhouse and retains a two-shot lead at the top of the leaderboard.
The players will start their fourth rounds on Sunday with organisers expecting them to have to play between nine and 12 holes on Monday.
Defending champion Brandt Snedeker said: "You realise it's a different week, and could be a Monday finish now and be ready for that.
"Sunday is going to be a weird day. You'll play a lot of golf. We need to get out here with the mindset that we need to make a lot of birdies, try to get back in contention and do as well as you can."
Woods, who has gone on to win 34 times out of 44 when holding at least a share of the 36-hole lead on the PGA Tour, said: "I have been out here long enough to know that this is part of the game."
Of his 14 closest pursuers, only Australian John Senden and American Nick Watney have previously won on the PGA Tour.