Kilmarnock boss Alex Dyer has promised to take no risks with Youssouf Mulumbu after confirming the midfielder has suffered an injury setback.
The former West Brom and Celtic star signed on for a third stint at Rugby Park last month after more than a year out of the game.
The 33-year-old Democratic Republic of Congo international made his return to action with a six-minute cameo against Dundee United before the international break.
He was missing completely, though, as Dyer's team lost at Aberdeen last weekend after tweaking a hamstring in training.
Mulumbu will be absent again as Killie host Hamilton on Saturday and Dyer will take a patient approach as he looks to build up his fitness.
He said: "Youssouf is not fit at the moment. He came on against Dundee United but after that he trained and felt a little bit of a twinge in his hammy.
"It might just be a consequence of the time he's had out. I'm not a physio so I don't know for sure, but it may be part of it.
"He's been out for a while but has trained hard since he came back in and wants to get involved in the side.
"He's felt a little twinge but I don't think it's a major problem and hopefully we might be able to get him back training next week and we'll take it from there.
"He's a quality footballer. It's nice to have him back but I'm not going to rush him and risk having him break down again. That's no good for nobody. When he's ready, he's ready."
Kilmarnock will face an Accies side hit by four coronavirus call-offs but Dyer knows his side are likely to go through their own Covid crisis in the months ahead.
"Of course we have sympathy for Hamilton," he said. "They are a good football club and we're all going to go through this.
"No-one is immune to this virus, this situation is going to happen to every club I'd think.
"We're lucky it's not happened to us yet. We've had a couple of little scares but we're OK.
"I hope everyone at Hamilton is fine and they're ready to go for the game tomorrow.
"But 100 per cent this will happen to other clubs. You don't have to be in sport to know it's happening all over the country.
"We're not exempt from it, so it's bound to happen. We just have to keep our house in order and deal with it as best we can.
"When we come up against a team that has had to deal with what Hamilton have this week, we just have to be professional and do the job.
"The most important thing is that we hope their players are fine. After that, we get on with the game.
"They have enough good players to bring into their side and we know it will be a tough game because it always is against Hamilton."