The star's mother is currently battling lung cancer
Jason Day withdrew from the WGC Dell Technologies World Matchplay less than halfway through his opening match on Wednesday night.
The Australian went into the tournament as one of the favourites for the event, having won the event last year. He was also victorious last year when the event was held in Arizona.
Day parred his first five holes in the match against Pat Perez, but found himself 2-Down. On the following hole, he double-bogeyed the par-5 sixth, and conceded the match.
Having struggled with back injuries recently, the golfer made it clear that was not the reason for his withdrawal. Speaking to press afterwards, an emotional Day revealed his mother has cancer, and he was to take an indefinite leave from the game.
"My mom has been here for a while [in America]. She has lung cancer. At the start of the year she was diagnosed with 12 months to live - this is so hard. The diagnosis is much better being over here. She's going in for surgery this Friday and it's really hard to even comprehend being on the golf course right now because of what she's gone through. She had a test done in Australia, and the doc said she was terminal and only had 12 months to live. I'm glad I brought her over here. And it's been really hard to play golf lately in this year."
"It's been very, very emotional, as you can tell. I've already gone through it once with my dad. And I know how it feels. And it's hard enough to see another one go through it, as well. So as of now I'm going to try to be back there with my mom for surgery and make sure everything goes right with her. I mean, once again it's been a very, very hard time for me to even be thinking about playing golf. And emotionally it's been wearing on me for a while. And I know my mom says not to let it get to me, but it really has."
"I didn't want to leave you guys out in the dust and try and speculate what was going on with me and my game and how I felt, if it was my back or anything. But I just wanted to make sure and get it out there that this is the reason why I've obviously pulled out this week because of my mom going for surgery to try and get rid of this mass that's in her lungs... I'm hoping for a speedy recovery for her, and we can get this behind us and she can live a long, long life."
Day's withdrawal casts a doubt over his participation on The Masters, which begins in a fortnight. In six previous appearances, Day has three top-ten finishes at Augusta including a second and third place finish in 2011 and 2013 respectively.