Ronnie O'Sullivan cast fresh doubt over his snooker future after another dismal defeat at the Bank of Beijing China Open.
Since early December, the former world champion has lost first-round matches at the UK Championship, Wembley Masters, Welsh Open and now this week's tournament in Beijing. He also withdrew from the German Masters, and has slumped to 10th place in the world rankings.
After losing 5-2 to Ryan Day on Wednesday, O'Sullivan said: "It's not great is it, but it is what is and there's not a lot you can do about it other than just keep trying. I can't really put my finger on it. It's very frustrating. It's not enjoyable. It's not fun for me. It'll give you a lot of grey hairs when you play like that. I don't know how much more I can take of playing like that."
He added: "I've said I would retire before but haven't, so I don't want to look silly, but I can't continue to keep playing that way. I'm not going to say I'm retiring but you never know, it's not looking good."
O'Sullivan has not won a match at a major ranking event since September's World Open, when he lost to Neil Robertson in the final.
The World Championship is coming up next month, and Dominic Dale awaits O'Sullivan in the first round. Normally O'Sullivan would be expected to brush Dale aside, but current form suggests it could be tight.
"I need to get home and see my family and get ready for Sheffield now," O'Sullivan said. "It's just around the corner."
Asked if a visa issue on his arrival in China had knocked his focus, O'Sullivan said: "There's no excuses here, I'm just not playing well and I'm getting beaten regularly.
"I'm just not producing - end of story.
"If I was potting balls I'd be sitting here buzzing."