Manchester City are sweating on the results of a scan on the knee injury sustained by defender Micah Richards in the 1-0 Carling Cup victory at Bolton Wanderers.
The 19-year-old England international had to be stretchered off after 73 minutes of the clash at the Reebok Stadium, before City won through thanks to an extra-time penalty from playmaker Elano.
After the win, Citizens head coach Sven-Goran Eriksson said: "Micah twisted his knee and will have a scan. Before that it is impossible to say if it is serious or not.
"I think he was hurt trying to turn. He says he will be fine, but let's wait and see what happens."
Meanwhile, Eriksson was pleased with the efforts of his team, as they bounced back from a 6-0 thrashing at Chelsea.
He added: "The spirit was there again and we defended very well, even in the last ten or 15 minutes when Bolton put a lot of players up.
"It was important to go through and reach the quarter-finals. I am happy about that. Elano remained cool to take the penalty and showed his experience."