Swansea manager Michael Laudrup is hopeful Ashley Williams will soon make his return from injury, but cannot give a definite date for when the defender may complete his recovery from an ankle problem.
The 29-year-old centre-half has featured just once in Swansea's last six games, and missed Wales' World Cup qualifiers against Macedonia and Belgium with the problem.
Laudrup has confirmed he will yet again be sidelined when Sunderland visit the Liberty Stadium on Saturday, which comes just 15 days before the eagerly-anticipated trip to face Cardiff in the south Wales derby.
Williams could return to training in the coming days, but Laudrup admits he cannot yet set a date for when he will be match fit, and will continue to adopt a cautious approach in order to make sure the injury does not become more serious.
He said: "If we are not careful it could become a chronic problem with him.
"He has not been at 100 per cent and that's not a good condition for a player to carry on playing because there are always doubts.
"You could go on for months always playing at 85 per cent and we don't want that, so it's better to wait.
"We wanted him back for this game against Sunderland but it is more important to get him back 100 per cent so he is comfortable when he is playing.
"I don't know when that will be. He's been training with the physios but the only training he has done with the squad since playing against Crystal Palace has been for 30 minutes.
"I will not force him to play because even if he is back training and no longer injured, to be fit to play 90 minutes is another thing, so he must come back when he feels ready to.
"I think he would like to play before we play Cardiff and if everything goes well it could be on Thursday (against Kuban Krasnodar) - but we won't risk anything and we've proven that already with him."
While Williams sat out the international break, his club colleague Michu made his debut for Spain against Belarus, after being called up by Vicente del Bosque following an injury to David Villa.
Laudrup believes the player and club should be tremendously proud of the achievement, and was delighted to hear the forward tell the Spanish media he plans to remain at Swansea.
Laudrup said: "I'm happy he said he wanted to stay, but we at Swansea should be more happy with the fact he was there.
"The day before Spain played I saw the squad and looked through the list of clubs their player played for. There was Barcelona, Real Madrid, Atletico Madrid, Manchester City, Chelsea, Valencia, then Swansea.
"It sunk in that it was incredible, the best clubs in Spain, and England, and we were represented too.
"It was a moment to be proud of that one of our players made it into that list."
Aside from the absence of Williams, Laudrup has had some good injury news with Michel Vorm (hand), Pablo Hernandez (hamstring) and Jonathan de Guzman (groin) all set to be fit to face the Black Cats, although Ben Davies is a doubt with a hamstring injury picked up in the defeat to Southampton.