The omens weren’t entirely promising from the off. Rory McIlroy strode onto the practice putting green - a matter of yards behind the first tee - and walked in JP Fitzgerald’s direction. The caddie had beaten him to the roped-off green by five minutes and presented his boss with two golf balls, both marked, and stood back to let the world number one get on with his preparations.

McIlroy threw the balls gently to the ground. The putter started its work. Hot, or cold? His starting range for putts was 15-18 feet and McIlroy worked the green, hitting one ball after the other, towards the empty holes. Putt. Miss. Putt. Miss. The sequence was continued for six straight putts, all with the same result. Not one effort found the tin cup.

Time to change tack, by reducing the distance to eight feet, McIlroy started the process again. At the second time of asking, his eighth putt in total, McIlroy finally sank a putt. Warmer.

Fitzgerald seemed undeterred, striking up a conversation with Scott Vail, the caddie to Brandt Snedeker.

Wisely, as it turned out, Fitzgerald had chosen to wear a t-shirt underneath the caddie boilersuit that is traditional wear for bagmen here. Vail was explaining, non-too-discreetly, that he had to shave the hairs on his chest so that it wouldn’t catch. Such are the conversations that pass the time and relieve the pressure of caddies, before the serious business of chasing green jackets get under way.

McIlroy’s last shot in a Major in 2014 was in tapping in to win the US PGA at Valhalla last August, a stroke made in near darkness. It gave him back-to-back Majors to go with his British Open success at Hoylake; but eight months have gone by since lifting the heavy Wannamaker Trophy and commencing this latest quest to complete the missing link in securing a career a Grand Slam.

The deadly accuracy of his PGA success in Louisville, however, was absent. This time, instead of aggressively firing at flags, McIlroy was forced on the defensive. McIlroy struggled to find any rhythm, as exemplified by his pulled tee shot into the creek in the trees down the left of the Par 5 second hole. That he salvaged a par, hitting his fourth shot from 160 yards to eight feet, at least confirmed his capacity to hang tough.

And hanging tough was how it was for much of a round, with McIlroy’s mental strength probably the strongest part of his game as he signed for an opening 71, one under par, that constituted his ninth straight sub-par round in the Majors.

On the Par 4 third hole, after a huge drive left him with a gentle pitch shot from 25 yards, McIlroy’s chip rolled halfway back down the slope. Again, he was forced to show his battling qualities. Again, he saved par.

But McIlroy only found two of the opening five greens in regulation, and his first bogey of the round arrived on the Par 3 sixth where, again, he missed the green and, in a replica of his efforts on the third, his chip failed to find the green. This time, instead of only rolling back halfway, it came scuttling down to his feet. This time, there was to be no reprieve. A dropped shot.

McIlroy bounced back with a birdie on seventh, where a superb drive was followed by an approach to six feet. His first birdie of the day brought roars, but the louder cheers and encouragement seemed to be headed in the direction of one of his playing partners.

Phil Mickelson remains a man of the people in these parts, with baseball terminology - "You're in the wheelhouse, Phil!" - used to encourage Lefty and let him know he was in the zone. Ryan Moore, the third member of the group, wearing grey and black as if to be as nondescript as possible, simply went about his own business. Mickelson opened with a 70, Moore a 74.

It was a tough front nine for McIlroy, though. He failed to birdie either of the two Par 5s - the second and the eighth - and, on the ninth, was again forced to make an up and down to save par. After a booming drive left him down by the walkway, McIlroy’s approach finished short of the flag and spun, immediately destined to roll back down the hill. Again, he was required to show grit. He pitched to 10 feet and rolled in the par saving putt.

But he couldn’t possibly keep the par-saving act going and, on the 11th, McIlroy fell victim to a hole which has penalised any poor shots. McIlroy’s bogey on the Par 4 entrance into Amen Corner move him to one-over.

“I just kept telling myself to be patient, it was a tricky day. The wind was swirling, the pin positions tough. I’m pretty satisfied with my day’s work,” said McIlroy, who birdied the 13th and 15th holes on the run home to edge in the right direction.

He added: “It could have been a round that got away. I just stayed patient realising that it’s a 72 holes golf tournament, not to press too much. That’s what I did. I feel with the way I am driving the ball, if I can keep doing that and just be a little more patient with my iron play and give myself more opportunities, I’ll hope to be right there at the end of the week.”