Lee Westwood needs a rapid return to form to stand any chance of retaining his place in Europe's Ryder Cup team.
The English former world number one is among several big names for whom this week's World Golf Championships in Ohio and the US PGA, which starts on 7 August, are crucial to their hopes of appearing at golf's biggest showdown at Gleneagles in September.
Westwood's fellow Europeans Luke Donald, Ian Poulter and Graeme McDowell also need to perform over the next two weeks.
For the Americans, the big two of Tiger Woods and Phil Mickelson have significant points to prove as the qualifying calendar builds to its climax. The US system ends at the PGA while the Europeans have until the Italian Open at the end of August.
Of the names to have defined the Ryder Cup over the past two decades, it is Westwood who looks most vulnerable.
The 41-year-old from Worksop has played in every edition since making his debut in 1997, with his team winning all but two of those matches.
Yet this year Westwood's chances of retaining his place hang by a thread. Captain Paul McGinley has stated the Englishman's need for improvement and time is fast running out.
Since winning the Malaysian Open by seven strokes, a week after finishing seventh at the Masters in April, his form has plummeted. He heads to the WGC event off the back of four missed cuts, the most recent coming in the Open at Hoylake earlier this month.
Somehow Westwood has to convince McGinley he's worthy of one of three wildcard picks. On the plus side, he does enjoy the Firestone course in Akron and must hope it can inspire a return to his best form.
Open champion Rory McIlroy heads the list of players who have already guaranteed their places in the side for Gleneagles. He'll be joined by Victor Dubuisson, Henrik Stenson, Sergio Garcia, Justin Rose, Martin Kaymer and Thomas Bjorn.
Welshman Jamie Donaldson is one good finish away from booking his spot as well, but is faltering with the finish line in sight. He goes to Ohio off the back of consecutive missed cuts at the Scottish Open and Hoylake.
Northern Ireland's Graeme McDowell is timing his run superbly, backing up his French Open win with top-10 finishes at the Open and at the Canadian Open last weekend. His current form and experience make him a prime candidate for a pick if he doesn't make it on merit.
The same applies to Ian Poulter given his proven record for Ryder Cup heroics. The Englishman is currently 12th on the list, but short of form having missed cuts in his last two outings.
There is no halfway cut at Firestone and Poulter has to make the most of his four rounds. In 11 previous visits, he has not finished higher than 13th in the Bridgestone tournament.
By contrast Donald hasn't been out of the top 10 since finishing runner-up there in 2011. He's also never been on a losing Ryder Cup team and currently occupies the last automatic qualifying berth.
Donald may feel most pressure from Stephen Gallacher, who is building a compelling case to follow his uncle Bernard in being a Scot to play a Ryder Cup on home soil.
Three-time skipper Bernard Gallacher played in the 1973 contest at Muirfield and his nephew has all the credentials to follow in those spike marks.
The current Scottish number one was fourth at Royal Aberdeen and 15th at the Open. As long as he stays around the qualifying mark, he must stand a fine chance of winning a captain's pick.
McGinley would surely love to have a Scot in his side, especially one who made a play-off at the Gleneagles PGA Centenary Course in the last pro event to be staged there before the Ryder Cup.
And what about the notion that Colin Montgomerie - Europe's victorious captain at Celtic Manor four years ago - could provide some Scottish influence? Surely not, despite his victories in the Senior's US Open and PGA.
|Ryder Cup results|
He was also runner-up to Bernhard Langer in the over-50s British Open at Royal Porthcawl last Sunday and some pundits are even pushing for both veterans to return to the European team.
Yes, they have put in very impressive performances, but it has been at a level appreciably inferior to the PGA and European Tours. In fact, Miguel Angel Jimenez is the best of golf's senior citizens.
The 50-year-old Spaniard has won twice this season, including his home Open, and automatic qualification is still within reach.
As for the Americans, skipper Tom Watson will be desperate to see some form from Woods who languishes 215th on the FedEx Cup standings. Indeed, the former world number one lies four places behind the 64-year-old American captain.
They seem distant memories, though. Never has there been more need for the 38-year-old to cast off the rust that was still so evident at Hoylake, where he finished six over in only his second tournament since March after returning from back surgery.
Woods has two weeks to climb into the top 125 to make the play-offs. Otherwise he could only head to Europe to find competitive action before Gleneagles and that's a highly unlikely scenario.
Watson is joined by a band of officials and television executives desperate to see Woods revive a season ruined by injury. Without doing that, it would be very hard to justify his place in the US side.
Nine players qualify automatically and, with double points available at majors, there is still plenty of scope for change.
Mickelson is currently 11th in the standings and, as long as he shows a decent level of putting form over the next fortnight, he will surely earn his place on the team one way or the other.
For the likes of Webb Simpson (15th) and Keegan Bradley (16th), the last two weeks of the US qualifying period will be very important if they are to retain their places in the team.
It promises to be a frantic fortnight. Watch this space.