Golf fans are fearing the worst for Tiger Woods after the American legend withdrew from the Genesis Invitational after just six holes on Friday due to illness. Playing in his first PGA Tour event of the year and first official tournament since the Masters last April, Woods called it quits after just 24 holes.

The 48-year-old hit his tee shot on the seventh on Friday, before he asked for a cart to be brought out and was driven off the course by a rules official. PGA Tour official Mark Dusbabek said on the telecast that Woods had an illness, and his withdrawal was not related to his ankle or back.

Rob McNamara, his long-time associate and vice president of TGR Ventures, reported later that Woods felt flu symptoms on Thursday night, which became worse when he woke up. “He had a little bit of a fever and was better during the warm-up, but then when he got out there and was walking and playing, he started feeling dizzy,” McNamara told a PGA Tour official.

“Ultimately, the doctors are saying he’s got potentially some type of flu and that he was dehydrated. He’s been treated with an IV bag and he’s doing much, much better, and he’ll be released on his own here soon.

Woods said he suffered a back spasm on Thursday when he shanked a shot horribly on the final hole of his opening round. He was 1-over par for his second round and projected just outside the cut when he called it quits.

Dusbabek had earlier said the back was not the issue on Friday. “Not what we’re being told by him right now,” Dusbabek said. “It’s an illness. He’s not feeling well. I’m sure that’s part and parcel to the reason, but he’s not feeling well. He’s feeling ill right now.

Woods was seeing with his head buried in his hands as he was driven off the course. He hadn’t played an official event since the Masters last April, when he also withdrew in the middle of the third round of the rain-delayed major. He played the unofficial Hero World Challenge in December against a 20-man field with no cut, and then took part in the 36-hole PNC Championship with his son.

The 15-time major winner had said he was hopeful of playing one tournament a month this year – including all four majors. That would theoretically mean that Woods will try to compete in either the Arnold Palmer Invitational or The Players Championship next month.