David Moyes conceded Sunderland are down to the "bare bones" after an injury to John O'Shea in the 2-1 defeat to Middlesbrough further stretched their already depleted squad.
With Younes Kaboul having left for Watford in midweek and Lamine Kone struggling with a back injury while reportedly angling for a move to Everton, O'Shea started alongside debutant Papy Djilobodji in the centre of defence as Paddy McNair was deployed in midfield.
But the veteran defender was replaced by Steven Pienaar in the 37th minute on Sunday and could be set to join Sebastian Larsson, Jan Kirchhoff, Lee Cattermole and Billy Jones on the sidelines.
Moyes acknowledged it is a difficult situation to manage but took some positives from their defeat, with Patrick van Aanholt halving the deficit in an improved second half after Cristhian Stuani's double had put Boro two up.
"I did not think we deserved to be 2-0 down at half time. After we lost John O'Shea, we did not get quite sorted. We did not take some chances but they did," said Moyes.
"We played well - we had a great level of intensity but ran out with 10 minutes to go. We have so any young boys and are at the bare bones.
"The boys did try to win and score in the second half but were unlucky. I took positives form the first half, we played well. Overall, they were fine.
"We are working really hard, everybody knows we are short and we will get the players."