Defending champion Ronnie O'Sullivan said he was troubled by a bad foot after reaching the fourth round of the Betway UK Championship with a comfortable victory over Thailand's Noppon Saengkham.
O'Sullivan, who is chasing the eighth UK title of his stellar career, was in dominant form at York Barbican, winning 6-2.
But the 43-year-old said he was struggling with "a really, really bad foot".
"I hope I am OK to play," O'Sullivan told BBC Sport. "It's an old running injury.
"I couldn't stop running forever so I got back to running four or five weeks ago and it's just really sore.
"I have to manage it. I don't want to pull out so will just have to run on the days I am not playing."
Breaks of 97 and 76 underpinned his success, with a spectacular pink to the corner pocket sealing victory in frame eight.
O'Sullivan did not drop a frame in the first two rounds, whitewashing Ross Bulman and Tian Pengfei.
And although Saengkham ended that sequence, he had no answer to O'Sullivan's all-round game.
O'Sullivan will meet China's Ding Junhui in the last 16 after he came through 6-4 against Ali Carter.
The 32-year-old Ding scored five breaks of over 50 to hold off a resilient Carter.
Three-time world champion Mark Selby won a scrappy encounter against Martin O'Donnell 6-3.
Selby's highest break was a modest 70 and he was far from his vintage best.
But O'Donnell failed to take his opportunities and a missed black in the ninth frame allowed Selby to secure a last-16 date with Matthew Stevens.
Stephen Maguire eased through with a 6-2 victory over his fellow Scot Graeme Dott, while Liang Wenbo overcame Eden Sharav 6-4.
Gary Wilson - who had breaks of 74, 103, 75 and 101 - overpowered Joe Perry 6-1, and there were also evening-session wins for Yan Bingtao and Michael White over Jack Lisowski and Mark Davis respectively.
