Casey is among a host of top stars unsure of a Ryder Cup place
Paul Casey's joint-third finish at the Open has left him still needing a wild card if he is to play at the Ryder Cup.
With six weeks until Europe captain Colin Montgomerie names his 12-man team, Casey is outside the nine players in automatic qualifying positions.
They are Lee Westwood, Rory McIlroy, Francesco Molinari, Luke Donald, Graeme McDowell, Ian Poulter, Martin Kaymer, Miguel Angel Jimenez and Ross McGowan.
The Ryder Cup takes place on 1-3 October at Celtic Manor in Wales.
Montgomerie, who announces his vice-captains for the event on Tuesday - with Thomas Bjorn and Bernhard Langer among the favourites - admitted he was delighted with the European showing at St Andrews.
"Things couldn't be going much better really when you look at the leaderboard, with Casey and Westwood and Kaymer and (Henrik) Stenson. They are all up there doing you proud," he said.
"We've had our first British winner of the US Open for 40 years (Graeme McDowell), Lee Westwood almost won the Masters, we're contending here again and who says we won't do so again at the USPGA in a month's time?
"Justin Rose winning twice in America... it's been a fabulous year for British golf, an amazing standard of golf, with British players battling against each other."
Casey is among those relying on being one of Montgomerie's three wild-card picks.
The world number eight is not the only top European player sweating on his place, though, with Rose, Stenson, Padraig Harrington, Sergio Garcia, Robert Karlsson, Ross Fisher and Edoardo Molinari all in the top 40 rankings but not, as it stands, guaranteed to feature.
United States captain Corey Pavin also faces some tough selection choices ahead of the three-day clash at Celtic Manor.
Only the top eight players in the US Ryder Cup table after the USPGA Championship at Whistling Straits on 15 August qualify automatically for the match.
With over 70 days before the first shot is struck at the Ryder Cup there is still plenty of time for potential team members to show even better form
Tiger Woods consolidated his seventh place in the standings despite his disappointing 23rd place at the Open, while Dustin Johnson, who finished joint 14th, is in sixth spot.
Pavin is following the example of predecessor Paul Azinger by watching three more tournaments before deciding his four wild card picks.
Sean O'Hair and Nick Watney were the top-ranked Americans at St Andrews after finishing joint seventh, but it was not enough to force either into the automatic Ryder Cup places, with Watney currently 14th and O'Hair a further five places back.
As it stands, Woods and Johnson are joined by Phil Mickelson, Steve Stricker, Jim Furyk, Anthony Kim, Lucas Glover and Matt Kuchar, with Jeff Overton and Ricky Barnes just outside the automatic spots.
Pavin names his four wild cards on 7 September, with the likes of Hunter Mahan, Ben Crane, Bubba Watson, Zach Johnson, Kenny Perry and last year's Open winner Stewart Cink all in or around the top 20.
"I certainly wish Americans had played better in general," Pavin said from his base in London, where he is getting ready to compete in next week's Senior British Open at Carnoustie.
"But there were good performances by Dustin Johnson, Rickie Fowler, Jeff Overton, Nick Watney, JB Holmes and Sean O'Hair.
"With over 70 days before the first shot is struck at the Ryder Cup, there is still plenty of time for potential team members to show even better form."