Newcastle United and England goalkeeper Nick Pope requires shoulder surgery and is expected to be out for four months.
The 31-year-old dislocated his shoulder when he dived to make a save during the closing stages of Newcastle's 1-0 win over Manchester United on Saturday.
Manager Eddie Howe said there is "still a chance" Pope could return before next summer's European Championships.
"He's naturally down because we've got huge games coming up and he's got the Euros ahead of him," Howe said.
"We're thinking of him because it's another strange injury for us. There's no doubt he needs an operation so he will be out for a period of time, we think around four months."
Pope, who joined Newcastle for an undisclosed fee in June 2022, joins striker Callum Wilson, winger Harvey Barnes, midfielders Jacob Murphy and Joe Willock, and defenders Sven Botman and Dan Burn among the club's injury concerns.
The former Burnley goalkeeper had played every minute of Newcastle's Premier League and Champions League campaigns this season.
But he had to be replaced by Slovakia international Martin Dubravka after 86 minutes at St James' Park having been unable to continue.
Following his injury it was reported
that Newcastle could use the January transfer window to replace Pope, with former Manchester United goalkeeper and current free agent David de Gea said to be interested in a move.
"I've seen a lot of media headlines regarding goalkeepers and other players," Howe said.
"We have not made any enquiries. If we were to recruit now we'd be recruiting in every area on the pitch. It's a chance for the other keepers to consolidate their positions."
This season Pope has kept five Premier League clean sheets - the joint-most alongside Crystal Palace goalkeeper Sam Johnston and Manchester United's Andre Onana.
The injury is a significant blow to Newcastle as they aim to continue making progress in Europe this season and once again make the Premier League's top four.
But it is also damaging to Pope's chances of regaining his place in Gareth Southgate's England squad before Euro 2024 next summer, having been overlooked since May. Pope has been capped 10 times by England.
"We are at the stage of the season where there are so many huge games coming up," added Howe.
"He's got the Euros ahead of him as well, which he was determined to try to be involved in, and there is still a chance of that for him.
"But I think his main determination is to come back for us. You never know what situation we will be in at that stage of the season."
Speaking on the Footballer's Football Podcast, Newcastle team-mate Wilson said Pope would be "a massive loss no matter how long he's out".
"He's single-handedly kept us in matches this season," Wilson added. "He's that difference at the back, but that's not to say that our other goalkeepers can't step up and now it's their opportunity to shine."