Grayson’s sides are renowned for being well organised and tough to beat.
However, Sunderland have conceded 21 goals in their opening 11 matches in the Championship.
Grayson has attempted to strengthen his backline by removing Lamine Kone from Sunderland’s defence and bringing in John O’Shea.
And Grayson claims that Kone is not being singled out for his poor performances.
“I wouldn’t say he’s struggling in terms of making a huge amount of mistakes, it’s just a general problem we’ve got as a team,” the Sunderland boss said.
“When you look at the goals we’ve conceded, I wouldn’t say that Lamine’s really been to blame for too many, but we have to be better as a group – as a back four and the players in front of them – to deny the opposition opportunities and basically to keep that ball away from our 18-yard box. That will give everyone a better opportunity.”
Kone was expected to dominate matches at Championship level, but the Sunderland defender’s struggles have continued.
The Ivorian was brilliant in his initial few months at the Stadium of Light, but he has badly under-performed over the past two seasons.
Sunderland are next in action at the weekend when they take on Queens Park Rangers, and a victory could lift the Wearsiders out of the relegation zone.