Casey: Patience is key

Tournament officials from the United States Golf Association had hoped to eventually resume play at the Long Island, New York, course when play was initially suspended at 10.15am (3.15pm BST). As the rain that swamped the greens and caused the opening round to be halted continued to pour into the afternoon, however, they decided no further play was possible and at 1.55pm declared play would resume at 7.30am on Friday.

"It's only going to get worse but we will see what happens," Casey said of the weather forecast.

With rain expected to continue into Friday - and Saturday promising a deluge equal to Thursday's - Mike Davis, the USGA senior director of rules and competitions, said a Monday finish was looking a distinct possibility as the body would not contemplate deciding the champion in fewer than 72 holes.

With the USGA also resisting calls to introduce a 'lift, clean and place' policy for muddied golf balls on fairways, world number three Casey, who will hope to restart on Friday two shots off the four-way lead at one over par, said the eventual champion would need to be have plenty of patience.

"You are certainly going to have to strike the ball very well but it's going to be the guy who keeps his head this week," he said. "Patience is paramount and you are going to have to deal with not only a very tough golf course but also some of the decisions that are being made like not being able to lift, clean and place. That's going to be very difficult and you are going to have be patient and expect some difficult lies and some mud-balls. That's the way it is."

Asked if that reduced the tournament to a lottery, the Englishman replied: "It does but hey, it all adds to the fun."

Davis insisted the US Open would be allowed to run its natural course.

"The USGA is firm on this, that we will not determine a national champion until we play 72 holes," he said. "So if that takes us in Monday or Tuesday, whatever."

Of the golf that did get played before the suspension, defending champion Tiger Woods needed to be at his combative best to stay on track for back-to-back wins. World number one Woods was one over par after six holes alongside Padraig Harrington and Angel Cabrera when play was supended with Americans Jeff Brehaut and Ryan Spears, Sweden's Johan Edfors and Canada's Andrew Parr sharing the lead at one under.