St Johnstone striker Nicky Clark could miss the start of the season.
Manager Steven MacLean confirmed the experienced forward has had an injury setback.
Clark was required to have an operation towards the end of the last campaign following an ankle problem and had been planning to hit the ground running.
But MacLean said: “Sometimes when you get your ankle or knee pinned, the screw can irritate.
“They have had to take it out and he is in a boot for two weeks.
“Then we can hopefully accelerate him as quickly as we can to get him back in the mix.
“He’ll just have to go through the process.
“We’re looking at the start of the league season. It might be after that.”
Dan Phillips has also not been taking part in early pre-season work after picking up an injury while away with Trinidad and Tobago.
“We’re hoping Dan will be back running in a week,” MacLean said on Friday.
“He came in to see the physio but we gave him a few days off because he has been away with Trinidad. He’ll be back in on Thursday to kick on.
“We’re probably looking at the first or second League Cup game for him. It all depends on how he reacts during his rehab.”
