Sunderland goalkeeper Vito Mannone will be out for a minimum of three months due to torn ligaments in his elbow, manager David Moyes has said.
The Italian underwent a scan in hospital on Tuesday after he was hurt in training, amid fears he had fractured his arm.
Moyes had still hoped the 28-year-old would be available to face Southampton on Saturday, but he will now spend a lengthy spell on the sidelines, leaving the Black Cats boss short of options and looking to bring in a new goalkeeper.
Jordan Pickford, who spent last season on loan at Preston, will get the nod at Southampton on Saturday after playing in
Wednesday night's 1-0 EFL Cup second-round victory over Shrewsbury
"It's not good news, he's torn ligaments in his elbow," said Moyes. "We're just finding out if it will require surgery or whether it can be put in a brace for the time being, but it's a significant injury. The doctor's first feeling is that it would be a minimum of three months [out].
"We've had two or three injuries where there's nothing you can do - [Lee] Cattermole has a double hernia and Seb Larsson had done his cruciate. Those boys we've missed them from day one and even a bit of pre-season.
"But to lose Vito makes it difficult. It just adds another one to the list in these last few days of the window.
"We'll definitely have to look for another goalkeeper - we only have a young goalkeeper [Max Stryjek] after Jordan [Pickford]."
Mannone started both of the Black Cats' opening Premier League fixtures this season and has made 59 appearances for the north-east club since arriving from Arsenal in 2013.
But Moyes has no qualms about pitching in Pickford at Southampton this weekend, adding: "I actually think that between him and Vito, it was very tight even at the start, but I think Vito with his experience got the jersey.
"It is a big step-up (for Jordan) from where he has been and it's not easy for young goalkeepers, but I'm confident that he'll be fine. I thought he played well the other night, what he had to do, so I'm confident."