Manchester City's teenage midfielder Phil Foden will be out for at least a month with ankle ligament damage just as he was beginning to make his mark in the star-studded side.
The 17-year-old suffered the injury in an accidental collision with an opponent while delivering a cross during Tuesday's League Cup quarter-final win at Leicester.
Foden was a star of England's Under-17 World Cup triumph in October, scoring twice in the final against Spain.
City boss Pep Guardiola has been keen to bring the Stockport-born teenager into his senior squad, with Tuesday's match his fourth appearance for City's first team.
"He's injured," said Guardiola. "It's not good. For the next fixtures, he will not be available. It's a ligament. He will out for a time."
Runaway leaders City are looking for a 17th successive Premier League win when they face Bournemouth at the Etihad Stadium on Saturday.
Guardiola is unsure whether playmaker David Silva will feature, having missed Saturday's 4-1 victory over Tottenham for personal reasons.
However, club captain Vincent Kompany is close to full fitness, having limped off with a muscle injury at half-time when City won 2-1 at Manchester United on December 10.
His setback was the latest in a long line of injury problems in recent years but his manager is hopeful this one is not too serious.
"He's much, much better," said Guardiola. "I think the next days he will be ready. I don't know whether tomorrow. I have to speak to him after the training session, we will see."
Despite Kompany’s fitness issues and John Stones's absence for more than a month with a hamstring problem, Guardiola has yet to decide whether to sign another centre-back in January.
Southampton's Virgil van Dijk and West Brom's Jonny Evans have both been cited as potential targets, but the City manager has indicated that he will not be panicked into a short-term signing.
"John Stones is coming back soon as well so we are going to decide," Guardiola said.
"I said many times, we are going to try. I don’t know if we will be able because the market is completely different than in summer time.
"We have to buy a player not just for the rest of the season but for the next two, three or four years."