Newcastle boss Alan Pardew confirmed goalkeeper Tim Krul suffered a dislocated shoulder in the 3-0 defeat to Sunderland on Sunday and will not play again this season.
The Dutchman landed awkwardly after punching away an Adam Johnson free kick and was immediately replaced by Rob Elliot in the second half of the Magpies' humiliating defeat to their bitter rivals this afternoon.
And Newcastle's afternoon took another turn for the worse when Pardew revealed he would be deprived of Krul's services for the Premier League run-in.
Although it lies 13th in the table, Newcastle is still looking over its shoulder as it is just five points clear of the drop zone with five games of the season remaining.
The Magpies were knocked out of the Europa League by Benfica earlier this week and Pardew must rally his troops without his No. 1 goalkeeper.
It is not the first time Krul, who recently returned to action after missing a month because of an ankle injury, has had problems with his shoulder.
The 25-year-old suffered a similar injury when he was on loan at Falkirk in January 2008.