Newcastle captain Jamaal Lascelles is expected to be out for “six to nine months” after scans revealed he needs surgery on a knee injury.
Lascelles ruptured the anterior cruciate ligament in his right knee during Saturday’s win over West Ham.
The 30-year-old will have surgery next week.
Fellow centre-back Sven Botman suffered a similar injury against Manchester City earlier this month and has also been ruled out for up to nine months.
Lascelles was forced off after 17 minutes of Saturday’s 4-3 win at St James’ Park.
In a statement, the club said: “After seeing a specialist consultant, he is expected to undergo surgery next week and will be out for six to nine months.
“Everyone at Newcastle United extends their best wishes to Jamaal for a full and speedy recovery.”
Tino Livramento, Emil Krafth and Miguel Almiron also limped off on Saturday as Newcastle’s season continues to be blighted by injury.
England goalkeeper Nick Pope has been out since December with a shoulder injury. Brazil midfielder Joelinton and Three Lions striker Callum Wilson have also been missing for extended periods.
Lewis Miley and Kieran Trippier are also sidelined, while Anthony Gordon will serve a one-match ban after being sent off for two yellow cards late on against the Hammers.