Newcastle captain Jamaal Lascelles will not play again until the new year due to a knee injury.
Lascelles was hurt during a tussle with Callum Wilson during the win over Bournemouth on Saturday and was replaced by Paul Dummett after just 20 minutes.
The Magpies have now had time to assess the injury and have determined the 26-year-old will miss at least six weeks of football.
Lascelles has been an ever present in Newcastle's Premier League side under Steve Bruce, starting all 12 games, but now leaves a considerable hole in the back line.
Dummett is on hand to deputise, while fellow central defenders Fabian Schar and Florian Lejeune are closing in on returns from injury.
Newcastle sit 13th in the table after back-to-back victories over the Cherries and West Ham, with a trip to Aston Villa on November 25 their first match without Lascelles.