Portrush - The Oosthuizen paired with Koepka at Open Championship
A look at five of those expected to challenge for the Claret Jug on Sunday:
1. Rory McIlroy (NIR)
The world No 3 tees up on home soil desperate to end a five-year wait to win a major.
McIlroy tends to be in the mix come the weekend at the Open, with top-five finishes in each of his last four appearances, including his solitary win in 2014.
After two wins on the PGA Tour this year, including the Players' Championship, McIlroy's confidence is restored and he also finished in the Top 10 at both the US Open and PGA Championship.
However, with a level of pressure even he will have rarely experienced to deliver in front of a home crowd, will McIlroy sink or swim?
2. Francesco Molinari (ITA)
The defending champion arrives in Northern Ireland cold after deciding against playing in either the Irish or Scottish Open to prepare on the links, instead saving as much energy as possible for his title defence.
Molinari has not had a stellar year, winning just once at the Arnold Palmer Invitational, but did get himself into a winning position at the Masters.
Ultimately, two shots into the water at Augusta cleared the way for Tiger Woods' sensational win. But 12 months ago it was the Italian who remained cool under pressure as others faltered in the final round to win his only major and the links may favour his game once more.
3. Brooks Koepka (USA)
The world No 1 arrives at the fourth major of the season having been in the top two for each of the first three.
Koepka has won four of the last nine majors he has played and was also runner-up at the Masters and US Open earlier this year.
Already the man to beat, Koepka has another weapon in his armoury this week as his caddie Ricky Elliott is a Portrush native and grew up playing the course.
Sixth in 2017 is Koepka's best effort at an Open Championship so far, but expect that to change over the coming week.
4. Justin Rose (ENG)
Rose's second-place finish at last year's Open was his best since finishing fourth as an amateur in 1998.
The Olympic champion was also in contention at the US Open last month until a poor final round cost him the chance of just a second major.
That was his last outing, but Rose got to Portrush a week ahead of the tournament and has been picking the brains of a former Open champion and Northern Ireland native Darren Clarke.
5. Tiger Woods (USA)
After ending an 11-year wait to win his 15th major at the Masters, Woods is going the extra mile in his preparations as he tries to win a fourth Open Championship by getting up at 1am at home in the United States to acclimatise to the time difference once he arrives in Portrush.
"If you want to succeed, if you want to get better, if you want to win, if you want to accomplish your goals, it all starts with getting up early in the morning," Woods said last week as part of a social media promotion with Nike.
His form since that memorable victory at Augusta, though, has been far from scintillating. Woods missed the cut at the PGA Championship and tied for 21st at the US Open.