And he was probably the calmest man in Yorkshire last Sunday as millions around the world tuned in to see the Sheffielder march to major glory at Augusta.
The reason England men’s lead coach Walker was unruffled while nerves were unravelling in clubhouses around the county was that he knew how well the 28-year-old had prepared for the moment.
“I turned to my son, James, with three holes to go and said, ‘He’s won this’,” recalled Walker.
“All the work he’s done over the years meant all the skills were there for Danny to put his foot down and get the job done.”
Defending champion Jordan Spieth dropped six shots in three holes after the turn, leaving former world amateur No 1 in the lead, which he reinforced with birdies at holes 14 and 16.
Then came a moment at his penultimate hole, after going long and left with his approach, when the Yorkshireman made impressive use of the short-game skills that have been forged under Walker’s tutelage.
Jonathan Plaxton, president of the Yorkshire Union of Golf Clubs, described the chip Willett faced as being “like trying to stop the ball playing down a marble staircase”. Willett finessed the shot to within inches of the cup to earn a par and maintain his momentum going up the last, which he also parred for a three-shot win.
Walker knew his former pupil would not have been fazed at hole 17 green because of a training regime incorporating “the international short game” challenge.
“It involves 12 shots – three chip shots, three bunker shots, three short pitches and three lob shots,” he explained.
“What you do is play the shots, measure how far they finish from the hole and that’s your ‘footage’.
“You do the exercise repeatedly and by recording your ‘footage’ you can chart your progress.
“Danny took on the challenge for years and when you have those scoring skills, I am not saying what Danny faced at 17 was easy, but it makes it easier because you have already played that thousands of times.
“Danny will have known exactly the spot he wanted to land the ball on, he’ll have known the loft he needed to land it with, and he will have known how much it would roll.”
Walker has rightly been the subject of much social media back-slapping this week for his part in Willett’s success.
He admitted: “Yes, I take immense pride from being involved. We spent a decade working together and a decade is a long time in coaching a player.”