The photo Rory McIlroy posted to Instagram on Wednesday shows his feet up, a black air cast around his left ankle, as he watches Wimbledon on television. The claret jug was positioned beneath the screen.

When it comes to a Grand Slam championship in his own sport, the world’s No. 1 golfer will be reduced to watching this year.

Two days after the stunning news that he ruptured a ligament in his left ankle, McIlroy pulled out of the British Open at St. Andrews, the first time in 61 years that the defending champion will not be in the field.

He injured his ankle over the weekend playing soccer with friends in Northern Ireland. McIlroy held out hope he could still make it to St. Andrews next week, but he decided it was not worth risking a full recovery.

“After much consideration, I have decided not to play in the Open Championship at St. Andrews,” McIlroy said on his Instagram post.

“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 percent healthy and 100 percent competitive.”

Ben Hogan in 1954 was the last British Open champion who did not defend. Hogan, who was nearly killed in an automobile accident in 1949, won the only British Open he played in 1953 at Carnoustie.

“We are naturally very disappointed that Rory will be unable to defend his title at St. Andrews next week,” the R&A said in a statement. “Rory will play in many more Open Championships and our primary concern is for his complete recovery.”

He was replaced in the field by Russell Knox, who grew up in Inverness in the north of Scotland and will be making his Open debut.

Though it wasn’t a big surprise that he withdrew — not after the photo Monday of McIlroy on crutches — it was no less jarring that golf’s best player would not be at the home of golf to defend his title.

His absence makes Jordan Spieth the favorite at St. Andrews in his quest for the Grand Slam. Spieth is only the fourth player since 1960 to have won the Masters and the U.S. Open in the same year.

“It’s hugely disappointing, especially with him and Jordan and everything that’s going on,” Graeme McDowell said from the Scottish Open.

“It was looking to be a really exciting Open for all involved. I’m sure he’s really disappointed. … No one would love to stop Jordan in his tracks next week more than Rory. With the fun rivalry going on and everything, he’s going to be gutted. I saw the golf course last Saturday. I believed that Rory was rightly a favorite. I thought he’d get it done around there.”

Still to be determined is how long the ankle injury keeps McIlroy out of golf.

He also is the defending champion in the Bridgestone Invitational at Firestone on Aug. 6-9, and the PGA Championship the following week at Whistling Straits. McIlroy finished one shot out of a playoff when the PGA Championship was last held there in 2010.

“We want him back. Everybody does,” Spieth said Tuesday at the John Deere Classic. “It’s unlucky, it’s unfortunate, and I’m sure he’s taking it harder on himself than anybody else.

“But I don’t think he did anything wrong, it was just an unfortunate situation. And hopefully, he rebounds quickly and gets back right to where he was.”

Spieth will have a chance to replace McIlroy at No. 1 in the world with a good finish at the John Deere and a victory at St. Andrews.

Tiger Woods is the only other No. 1 player to miss a major championship — the British Open and PGA Championship in 2008 recovering from reconstructive knee surgery, and the Masters last year when he had surgery on his back.

Knox was first alternate from the world ranking published Monday, and he was hopeful he would get into his first Open.

This wasn’t what he had in mind.

“Everyone is gutted for Rory,” Knox said after his pro-am round at the Scottish Open. “He is in the prime of his career and would have had a great chance to win there. Nobody wants to get in because someone else got injured. It’s a horrible way to get in, I guess, but I’m very happy I’m in the field.”

McIlroy has never won at St. Andrews, though the Old Course is special to him. It was at the Dunhill Links in 2007 that he finished third to earn his European Tour card.

And he tied a major championship record with a 63 in the opening round of the 2010 British Open at St. Andrews, only to follow with an 80 when a big wind arrived the next day. He tied for third that year.

He put a scare into the leaders at Chambers Bay in the final round of the U.S. Open, closing with a 66.

“It bodes well for the rest of the summer the way I’ve hit the ball this week,” McIlroy said before leaving Chambers Bay.

“And I’ve got a couple of weeks to work on my putting and get that up to the shape that it has been in. If I can do that … I’m really excited about what can happen over the summer.”