Rory McIlroy's ankle injury that has left him unable to defend his Open title at St Andrews next week will be one of the biggest regrets of his career, says former U.S. Ryder Cup captain Paul Azinger.
World No.1 McIlroy suffered a "total rupture" of the anterior talofibular ligament in his left ankle while playing soccer with friends. The four-time major winner announced on Wednesday that he would not be able to compete for the year's third major at the Home of Golf, where he carded an opening 63 - the lowest round in Open history - in 2010.
"I pulled out of tournaments because I sprained my ankle and I had the shoulder injury from pulling the plug out of my boat," said Azinger, working as an analyst for ESPN.
"You can't live in a bubble. Golfers are athletes, too, and Rory is an athlete, and he likes to play soccer.
"But it's an unforced error, and I think it's going to be one of the greatest regrets he'll ever have as a player, to have to look back on his career and realise that he didn't get to defend at St Andrews.
"We can't live in a bubble, but you have to be sensible. It didn't need to happen. He did it to himself and it's unfortunate, and it makes all of us sad, but him more than anybody, I'm sure.
"It's going to hit Rory. It'll hit him like a ton of bricks when the bell rings on Thursday and he's not there. He's going to have a lot of reflecting to do, and maybe he'll have to slide into a little bit of a bubble. This is an unforced error and it's a great opportunity lost. It's likely he'll never get this chance again and he's going to really feel that pain, I think, once the bell rings on Thursday."
McIlroy's defence of the Bridgestone Invitational in a month's time and the following week's US PGA Championship at Whistling Straits is also in doubt. Medical experts are forecasting up to three months out.
With Jordan Spieth already hot on the Northern Irishman's tail, McIlroy's No.1 ranking spot will now be under even more threat as the Texan makes his way to St Andrews on Monday looking for the third part of a calendar grand slam after Masters and U.S. Open victories earlier this year.
Broadcasting his decision via Instagram, McIlroy wrote: "After much consideration, I have decided not to play in the Open Championship at St Andrews. ''I'm taking a long term view of this injury and, although rehab is progressing well, I want to come back to tournament play when I feel 100% healthy and 100% competitive.
''Thank you for all your support and best wishes. I hope to be back on the course as soon as I can."
McIlroy is the first player not to defend his Open title since Ben Hogan in 1954, Hogan having won the Claret Jug at Carnoustie in 1953 in his only appearance in the event.
A statement on the Open Championship Twitter account read: ''We are naturally very disappointed that Rory will be unable to defend his title at St Andrews next week. ''Rory will play in many more Open Championships and our primary concern is for his complete recovery. Everyone associated with The Open wishes Rory the very best as he looks to return to full fitness.''