Copenhagen coach Stale Solbakken has revealed his fear that defender Mikael Antonsson could miss their Champions League encounter with Chelsea on Wednesday evening.
The centre-back has strained a muscle in his right buttock and is facing a race against time, according to his coach.
"It is a struggle against the clock," said Solbakken, according to uefa.com. "The way things look now, we will not make a final decision until the day of the game."
The Danish champions lost the first leg of their last 16 tie 2-0 at home last month and will be without suspended defender Zdenek Pospech for Wednesday's match at Stamford Bridge.