Kevin De Bruyne gave Manchester City a scare by coming off with a left knee injury near the end of a 2-0 win over Fulham in the English League Cup round of 16 on Thursday.

The Belgium midfielder, who has just returned from two months out with ligament damage in his right knee, winced after Fulham defender Timothy Fosu-Mensah landed on him as they competed for the ball. De Bruyne attempted to play on, but slumped to the ground moments later and then walked off in the 86th minute.

"He is being checked by the doctors," City manager Pep Guardiola said. Asked if he was worried about the injury, Guardiola said, "I don't know right now."

With most of City's star players given the night off, one of its brightest young talents took his opportunity to impress in a routine win over an opponent that has now lost five straight games in all competitions and has just one win in 10 games in the Premier League this season.

Brahim Diaz, a 19-year-old Spanish forward, scored a goal in each half at Etihad Stadium and was given a standing ovation when he was substituted in the 78th after making only his second competitive start of the season.

British newspapers reported this week that Diaz was likely to leave City next year over his frustration at a lack of playing time since moving from Malaga in 2016, and Guardiola said he understood the situation.

"They know how we want to protect them," Guardiola said of Diaz and other highly regarded young players. "They know how we tried to help them in the particular way we want to play.

"We want him. But, in the end, it doesn't depend on us. It's the desire of them, so we insist we want him. But his agent, and him, finally decides. No change of opinion now because he scores two goals, But in the top teams like here ... it's not easy to find space. He knew that in the beginning and he decided to stay."

Diaz's first goal was fortunate, his shot taking a deflection off Fulham striker Aleksandar Mitrovic and flying past flat-footed goalkeeper Sergio Rico.

He doubled the lead in the 65th by slotting a shot high into the net from close range after Gabriel Jesus' curling effort came back off the post.

City, the defending League Cup champion, will play either Leicester or Southampton in the quarterfinals. Their game was postponed this week following the death of Leicester's owner and four other people in a helicopter crash on Saturday.

With the cup game squeezed in between two Premier League fixtures in a six-day span, Guardiola took the opportunity to play many of his fringe players. Raheem Sterling and Sergio Aguero were among those who didn't make it off the bench.

De Bruyne was given a start, however, and impressed before his injury with his teasing crosses and passes.

"I think today, Kevin is back," Guardiola said. "It was the Kevin we know.

"Hopefully what happened in the last minutes is not serious."