Lee Cattermole is a doubt for the trip to Oxford United on Saturday.
Cattermole was absent from the Black Cats squad as they beat AFC Wimbledon 1-0 on Saturday .
The influential midfielder had picked up an injury during training late in the week.
"Lee picked up an ankle injury on Thursday," Jack Ross said.
"He's likely to be out for a week or two."
Sunderland are heading into an immensely challenging schedule.
After the clash at the Kassam Stadium, Sunderland play three times at the Stadium of Light in a week.
Blackpool, Accrington Stanley and Gillingham are the visitors.
Ross is hoping that deadline day signing Will Grigg will be able to play a significant part in that demanding run.
The 27-year-old has not played since January 19th due to an ankle problem but after doing some fitness work on Saturday morning, he is expected to join full training in the middle of this week.
Should that go to plan then he will be part of the squad on Saturday.