"It sucks" – J.J. Spaun reveals unusual injury that ended his PGA Tour season

J.J. Spaun believes sleeping in an awkward position led to a muscle strain that forced his withdrawal from the Tour Championship. 

The American was one of just 30 golfers to qualify for the PGA Tour's season finale at East Lake Golf Club in Atlanta.

But the former U.S. Open champion was forced to walk off the course in agony after hitting his tee shown on the 6th hole. 

Spaun, who was 4-over at the time, said he had experienced the same issue at last year's Open at Royal Portrush. 

"When I sleep with too high of a pillow and I'm kind of like that for so long, it disturbs like the rhomboid muscle in there," he said.

"But the other side wasn't hurting my backswing last year, but it's on the right this time. 

"It's something I've dealt with on the other side of my back, but not this side."

Spaun added: "Obviously it calmed down last year, and I was fine. Hopefully just a few more days. 

"I wish the tournament started another day later or week, then I'd be final probably."

Spaun said he woke up Tuesday morning with a sharp pain in his shoulder blade. 

"It flared up pretty bad," he said. "I couldn't play any holes after hitting balls for about 45 minutes.

"Wednesday I figured it would be a lot better. It kind of was. I couldn't move my neck or my head either direction. Took a few sandwich swings yesterday, and it's just basically like a knife in my right shoulder blade."

Spaun said he tried to push through the pain but realised he was nowhere near where he needed to be to compete at the highest level.

"I just didn't want to cause any further damage before I assess this correctly and see what's going on in there," he said. 

"It's improving day by day. I just think I've got to take a few days off golf, maybe a week or so, and I should be fine. 

"I didn't want to make a naive decision by pushing through to finish 30th. 

"I wasn't playing my best, and it's just hard to complete a backswing right now.

"It sucks to end the year this way, but that's life. 

"I turned 36 last week, and I think maybe that's just kind of what happens when you're in your mid-30s now."

Spaun's playing partner, Min Woo Lee, played the remainder of the round by himself. 

The Australian vaulted to the top of the leaderboard on day one and will begin the second round with a two-shot advantage over Chris Gotterup, Viktor Hovland and Collin Morikawa. 

World number one Scottie Scheffler is three back, whilst Masters champion Rory McIlroy is six shots off the lead. 

Scheffler is playing the season finale one week after recovering from a bout of hand, foot and mouth disease. 

He told reporters he's 95 per cent healthy and revealed, rather amusingly, that Matthew Fitzpatrick though the American was angry with him during last week's BMW Championship. 

Fitzaptrick was confused as to why Scheffler didn't speak to him over the first two days of the tournament at Bellerive Country Club in St. Louis. 

But Scheffler, who had ulcers in his mouth, just couldn't speak.