Woodland will play with Northern Irishman Rory McIlroy, the 2014 British Open champion, and England's Paul Casey in the first two rounds at Portrush.
Such is four-times major victor Koepka's belief that caddie Ricky Elliott can give him valuable "inside info" on the course that he even ignored a practice round invitation from Tiger Woods. He tied for 21st at the 2019 U.S. Open.
Clarke, 50, lifted the Claret Jug at Royal St George's in 2011 but has missed the cut in three of the past four years.
It only took a phone call to put things in motion.
"It's not quite as sharp as I'd like to have it right now", Woods said Tuesday morning after a seven-hole practice session at Royal Portrush. He was joking on the phone.
"(I) definitely have a little bit more confidence having him on the bag this week, knowing this golf course so well.
"I don't know what I'll do in the future", he said about his eating habits. "He's pretty laid back".
Woods used as references Greg Norman and Tom Watson, two former British Open champions who almost won in their 50s because length is not as paramount at Augusta National or the other two US majors. He hasn't played at all since an unspectacular run at the U.S. Open, and he's played exactly one non-major event since the Masters.
McIlroy made a quick stop at Portrush en route to the Scottish Open, where he tied for 34th on Sunday. "I think that's a taste of what we're going to get this week".
"The first day and a half was tough, but after that I found that I didn't crave food, I felt better, my energy levels were better, my focus was better", said Mickelson. He said he texted Koepka, hoping to get some advice on the course.
In the last 11 majors he has four wins and four other top-six finishes, but outside of golf's premier events this year he has been less impressive with just three top-10s in 11 regular strokeplay events. "To be so consistent, so solid", Woods said.
"That's the first time I've ever signed a false leg", said Mickelson, a man who regularly spends hours writing autographs for fans post-round.
"I'm well aware of the challenges ahead", Molinari said Monday on the first day of official practice at Royal Portrush.
Brooks Koepka is in the field for this week's Open Championship.
If Tiger Woods' golf career were one of those old-school arcade games, he'd be the guy with the initials TW beside every one of the top 10 scores.
That prompted the fasting, which Mickelson has read about extensively during the last two years in various scientific studies. Now it doesn't matter to me. "And a lot of it was trying to qualify for certain events, trying to get into the playoffs ..." He hasn't won the major since 2006.
With his trust in his own ability to deliver the big shots and his trust in his caddie's ability to deliver that little bit of extra insight on a course that hasn't hosted the British Open since 1951, Koepka is on the short list of favorites this week.
He praised Dave Alred, the performance coach who has worked with rugby stars Wilkinson and Johnny Sexton for helping him become mentally stronger.