MANCHESTER, England -- Manchester City are sweating on a knee injury to Kevin De Bruyne after he limped off out of their 2-0 Carabao Cup victory over Fulham on Thursday.
The Belgium midfielder was making just his second start after he missed two months of the season with a ligament injury.
But De Bruyne appeared to hurt his left knee in a tussle with Fulham defender Timothy Fosu-Mensah and left the pitch shortly after the incident.
Asked about De Bruyne's injury, Pep Guardiola told a news conference: "He's being checked by the doctors."
Asked if he was worried about a problem, the City boss added: "I don't know."
It was the only sour moment on a comfortable night for City as they eased into the quarterfinals of the Carabao Cup. Young Spanish forward Brahim Diaz scored both goals either side of half-time. Guardiola said he was impressed by the 19-year-old and fellow Academy products Phil Foden and Aro Muric.
"Everybody was good," Guardiola said. "Brahim made two goals, We didn't concede too many chances but Aro gave us good security when the ball was there. Phil plays a good level every time he plays. I wouldn't say just one.
"We made an excellent performance without the ball in terms of how aggressive we were. They have the quality to play even though they are not in a good moment in terms of results.
"We played like the competition and game deserved. We were clever and made the space and created enough chances. I'm so satisfied and happy for the victory."
Brahim's future remains uncertain with the teenager still to sign a new contract and his current contract running out at the end of the season. Real Madrid are among the clubs interested in him and Guardiola says they will do everything they can to convince him to stay at the Etihad Stadium.
"He knows the desire we want for all young players," Guardiola added. "They know how we want to protect them. He understands we try to help him in the way we want to play.
"We want him, but at the end it doesn't depend on us; it is the desire of them -- his agent, him, family, they decide.
"My opinion doesn't change because he scored two goals. The opinion of us is so high. To compete with Leroy [Sane], Raz [Raheem Sterling], Riyad [Mahrez], Bernardo [Silva], Sergio [Aguero], Gabriel [Jesus] it is not easy to find space.
"He knew that from the beginning and he decided to stay. We are delighted to and will do absolutely everything to keep him with us. But after that he will decide. It's simple."