Donald and Casey close in on big FedEx prize

And so could Paul Casey, the world number seven, who will be mountain biking in Canada rather than playing at Celtic Manor after his omission.

The two English stars have opened the Tour Championship in Atlanta -- the final leg of the money-spinning FedEx Cup play-off series -- with four-under-par rounds of 66 to share top spot with Australian Geoff Ogilvy.

The tournament title alone is worth £860,000, but the overall winner of the play-offs is given £6.4m extra.

That is guaranteed to be Casey's if he wins on Sunday, while should Donald triumph he can be denied the jackpot only if either of the current top two points leaders, Matt Kuchar and Dustin Johnson, finish second.

Since they lie 19th and 20th in the 30-man field after starting with 72 and 73 respectively, Donald and Casey -- already with one second place each in the series -- might yet be in a head-to-head come the final round.

"It's early days," said Donald. "Anything can happen -- but it's nice to position yourself well. The course is firm and fast and that makes it play difficult, but if I could do the same (in) the next three days I would take it right now."

Casey, making his debut in the event, was in the water on the short sixth -- "I haven't hit that green all week from the back tee," he said -- but it was his only mistake.

He turned in 33 and then picked up more shots on the 10th and long 15th.

Defending champion Phil Mickelson, meanwhile, had two eagles on the back nine, but still had to settle for a one-under 69.

Needing a top-two finish to take over as world number one from Tiger Woods at the 12th attempt this year, Mickelson sank a 115-yard pitch for a two at the 12th and then rolled in a 14-foot putt three holes later for his second eagle.

Mickelson admitted he was using the event to fine tune his game ahead of the Ryder Cup.

He said: "I think everybody on the team is using this as a way of keeping their game sharp in addition to trying to win the biggest prize on our Tour."