Shane Lowry, a team-mate of McIlroy when Ireland won the European amateur title six years ago and stablemate now, is his opponent in Wednesday’s opening round at Dove Mountain.

Sixty-seven places separate them on the world rankings but McIlroy, runner-up to Hunter Mahan last year, needs to be on his guard on a day that also sees a clash between the two other Irish golfers in the field – Graeme McDowell and Padraig Harrington.

Twelve months ago, top seed Luke Donald lost to bottom seed Ernie Els, the same happened to Steve Stricker against Ross McGowan three years ago and, in between, Lee Westwood was knocked out in the second round by Nick Watney.

Lowry, winner of the 2009 Irish Open when still an amateur, was in line to face Tiger Woods until Swede Fredrik Jacobson, in the field as the replacement for injured Brandt Snedeker, finished joint third at the Northern Trust Open in Los Angeles.

“I suppose I would rather (play) Rory,” Lowry said before knowing which of the two superstars it would be.

“I would be intimidated if I played Tiger. Since I started golf it’s always been Tiger who’s been the greatest. Standing on that first tee against him would be nerve-racking.

“I’d enjoy playing Rory and there probably is a bit of pressure on him, what with the change of clubs and having not played for a month since missing the cut at Abu Dhabi.”

But Lowry also told the Daily Telegraph: “Rory is Rory – he’s still the best in the world. It’s funny, we’ve never played against each other before, despite coming through the amateur ranks together.

“The way I look at it is that, whoever I play, I’ll have nothing to lose and everything to gain. This is going to be a great experience and a great chance to prove myself against the best.

“If I play my best golf I’ll have a really good chance of beating whoever I’m up against. I’ll tell myself that I came up against the best in the Irish Open (McIlroy was in the field) and a nobody – and I managed to win that.”