Sunderland manager Chris Coleman has said that the club's inconsistency in achieving results has been the main frustration in his time at the Stadium of Light.

Coleman, who was appointed in November following the sacking of Simon Grayson, has not been able to string back-to-back wins together during his tenure with the Black Cats.

The last time Sunderland achieved such a run was in November 2016, something which has caused the Welshman concern while in the North East.

"That's the frustration. We're not getting walloped each week and then when we win, we think 'this is it'," the 47-year-old told the Sunderland Echo.

"We must start putting runs together, back-to-back wins to make the table look better and it gives you confidence, but we haven't done that all season.

"There's a lack of belief and key areas where we must improve with a little bit of help from outside."

Sunderland, whose last win came at the end of December against Nottingham Forest, currently prop up the Championship table and are two points adrift of safety.