Raphael Guerreiro remains in talks with Borussia Dortmund, the Bundesliga club having reportedly offered the defender another contract extension.
The Portugal full-back is said to have been the subject of interest from Paris Saint-Germain and is out of contract at the end of the season.
Dortmund run the risk of losing Guerreiro on a free transfer if they cannot sign him to fresh terms and allegedly offered him a three-year deal worth €5million a year.
But Dortmund sporting director Michael Zorc gave little away on the progress of their discussions in a media conference ahead of Friday's Bundesliga clash with Cologne.
"We are still in talks," Zorc said. "I cannot tell you a tendency yet.
"We have to wait, we're not the only ones who decide."
On possible changes to the squad during what is left of the transfer window, he added: "It's just over a week's time. There may be something else happening, but I cannot promise that."
Mario Gotze had to come off the bench in Dortmund's 5-1 demolition of Augsburg to start the league campaign.
Asked about the World Cup winner, coach Lucien Favre said: "One year ago he was in a similar situation.
"He has already played 20 minutes against Augsburg. We have some competition, and Thorgan Hazard and Jacob Bruun Larsen can play in the attack. Mario can also play behind the striker.
"It will be a difficult game. We have seen Cologne several times. They have found a good base and quality in the team.
"They press very hard and with intensity. We have to be prepared for everything."