(CNN) -- Paul Casey may have been left out of Europe's Ryder Cup team, but the Englishman is in prime position to collect the $10 million prize for winning the FedEx Cup playoffs.
Casey needs to win the Tour Championship at East Lakes this week to scoop the massive end of season bonus prize and shared the lead with fellow countryman Luke Donald and Australia's Geoff Ogilvy after the first round.
The trio finished on four-under 66, but Casey is the only player in the top five of the standings, who could all claim the playoff series title and the jackpot with a win, to break par in Atlanta.
Casey grabbed three birdies in a row around the turn to put himself in prime position but said he was not trying extra hard to prove a point after being denied a captain's pick by European skipper Colin Montgomerie.
"I'm not getting wrapped up in any sort of extra motivation," Casey told the official PGA Tour website.
"I don't need extra motivation. I'm motivated enough."
Ironically, Donald, who did get the nod as one of three selections by Montgomerie, could also deny Casey the bonus pool.
Should he win, he can only be beaten if either of the current top two of Matt Kuchar and Dustin Johnson finish second. They lie 19th and 20th in the 30-man field after 72 and 73 respectively so have work to do.
The other sub-plot in Georgia surrounds the ongoing battle for the world number one spot and defending champion Phil Mickelson is well-placed after an opening one-under 69 - one of only nine players to break par.
Mickelson, who needs a top two finish to supplant Tiger Woods at the top of the rankings at his 12th attempt this season, had two eagles on the back nine but also struggled at times.
"It was a challenging test. There were some good scores and some high ones," he said.
"I was able to shoot one kind of in the middle there with one-under par, and I'll gladly take it. It's a better position than I started last year."
Woods is not playing at East Lakes after failing to qualify into the top 30 places, but will team up with Mickelson for the Ryder Cup in Wales next week.
Jim Furyk is in fourth place after the first round after a 67 and South Korea's KJ Choi carded a 68 for fifth.
Mickelson was joined on 69 by Australian Jason Day, Hunter Mahan and Kevin Na.