Pep Guardiola does not know if Gabriel Jesus will play for Manchester City again this season.
Brazil striker Jesus has undergone surgery to repair a broken bone in his foot and could be sidelined for up to three months.
The 19-year-old has made a big impact since joining City in January but fractured a metatarsal during Monday's Premier League victory at Bournemouth.
He is now in Barcelona, where he has been treated by renowned surgeon Dr Ramon Cugat.
Guardiola said: "Last night he had an operation. It was good, really good.
"Now it is important he makes a good recovery. He comes back when he is fit, I don't know, at the end of the season or next season."
Asked if there was a chance Jesus could play again this season, Guardiola said: "I don't know. People say between two and three months."
Jesus' absence is expected to mean top scorer Sergio Aguero will be back leading the line. The prolific Argentinian, who has scored 18 goals this season and 154 since joining the club in 2011, has started the last three games on the bench while Jesus has taken the chance to shine.
That situation has sparked fresh speculation over the long-term future of Aguero but Guardiola has been pleased with his attitude.
Speaking at a press conference to preview Saturday's FA Cup fifth-round tie at Huddersfield, Guardiola said: "He was from the beginning of the season, not just these three games, more than good.
"When Sergio was in the team, in the last minute against Swansea or the last game in Bournemouth, he came in and played good. I don't have doubts about the quality - that was always there - or the behaviour in the team."
Guardiola admits Aguero coming in for Jesus is not a straight swap and the team may play differently as a result.
He said: "Sergio has to do what he has done all of is career, nothing more. When Gabriel played in the last three games I didn't ask him to do what Sergio does, and I'm not going to ask Sergio to do what Jesus did.
"Every player has his quality. Just go there, play as best as possible, that's all."
On another major selection issue, Guardiola did not indicate whether goalkeeper Willy Caballero, who has played in the last four games, would continue or Claudio Bravo would be recalled.
"I am going to decide tomorrow," he said, before adding he would make "some" changes.
Guardiola expects a test from Huddersfield, who are third in the Sky Bet Championship.
He said: "Right now Huddersfield are in a big moment. They are doing really well and a lot of confidence.
"Yesterday there was a rugby game in their stadium, so we can imagine the conditions of the pitch, but it is a final for us.
"In the cup there are no second chances. You are in or you are out in that competition. We are prepared to fight and go to the quarter-finals."
The Terriers have been aided this term by a player on loan from City, Aaron Mooy, but he is not permitted to face his parent club.
Guardiola said: "He is playing amazing this season, we are glad of that. We are going to consider what will happen at the end of the season."