The Irishman also believes St Andrews, venue for next week’s event, is the one course on the Open rota where McIlroy could turn up without a practice round if he has to leave a decision on his ruptured ankle ligaments until the last minute.
McIlroy’s hopes of defending his title appear to be slim after he posted a picture of himself on social media with his leg in a brace following the injury sustained in a football kick-about with some friends back home in Northern Ireland.
However, Harrington found himself in a similar position – a wrist injury in his case – heading into the 2008 Open at Royal Birkdale yet still managed to become a back-to-back champion following his first major success at Carnoustie 12 months earlier.
“I injured myself five days before The Open,” he recalled. “The first time I put the wrist under pressure was the sixth hole on the Thursday and, when I did, it was fine. I wasn’t playing under an injury. I just couldn’t prepare because of an injury – which probably did me some good, looking back. I just walked around with a wedge and a putter on the Wednesday, played a few chips, got the feel of the greens.
“So it interfered with my preparation, although it might have even helped my tournament. But I certainly wasn’t playing with an injury. I tested it after six holes and it worked.
“It could be completely different circumstances to what Rory is facing, depending on how he recovers. Only he will know the next step. I’m assuming he’ll be finding out the extent of the damage – and I’m sure he’ll have the quickest recovery available. It just depends how bad it is.”
On the fact The Open is being held at St Andrews, Harrington added: “The great thing is that he doesn’t need to turn up at the Old Course and play a load of practice rounds. Nobody needs that. Of all the Championship venues we play at, that’s probably the one where you can almost just turn up and play.
“The Masters is like that too. If you turn up and get the pace of the greens, hit a few chip shots, there is nothing tee to green you are going to learn on Monday, Tuesday or Wednesday.
“That’s especially true at St Andrews, where it only becomes a little different with a slight change of wind. So he doesn’t even need to play one practice round. He just needs to be able to put pressure on his left foot.
“That’s a big problem. You can play golf with a bad right ankle without too much trouble. But it’s difficult putting weight on your left side. It’s very hard to play golf if you can’t press on your left side.”
Harrington revealed he’d suffered a similar injury in his amateur days, but is confident McIlroy’s recovery period will be a lot shorter than his. “I did the same thing in ’91, but didn’t get it treated quickly enough or properly. And still to this day I work on my left ankle because of that injury. It took a long time to clear up,” he said.
“But we can be sure that won’t be the case with Rory at all. I didn’t know what to do with it at that stage – and left it too long to get it sorted. The quicker you get it sorted the better and it looks like Rory has done that. I know he’ll have the back-up team to help him get better as quickly as possible. It happened on Saturday, so 12 days – that’s a reasonable amount of time.”
Andy Murray, a keen football player, has also sent his well wishes to McIlroy.
Speaking from Wimbledon, the Scot said: “I sometimes play football. I always play with ankle braces and stuff in case, you know, something happens.
“But, yeah, it’s really, really unfortunate. Hopefully he’s OK.”