Sunderland manager Tony Mowbray has admitted that his side's inconsistency has been a problem.
Mowbray has won four of his 13 games in charge but is yet to record back-to-back victories.
He said: "There is a consistency level issue. We're really good for 45 minutes, either at the beginning or the end."
Sunderland won at Huddersfield Town last Wednesday, but they could not back that up at the Stadium of Light as Mark Harris' goal second-half goal won it for the Bluebirds.
Mowbray, who replaced Alex Neil in August, has seen his team win won only one of their past five matches in front of their own supporters.