Sunderland captain John O'Shea feels the squad still needs additions.
Sunderland have bolstered their defence with the addition of full-backs Billy Jones and Patrick van Aanholt, but they are still short in central defence, central midfield and on the flanks.
"We'll also need a bit more help there as well, not just in defence," said O'Shea to the Evening Chronicle.
"The manager has pointed that out, just to get the competition which is needed to bring strong games in training and keep lads on their toes.
"It is nice to have natural full-backs in place, especially when you are doing work on team shape and things.
"We like our full-backs to push forward. Billy could have been on the scoresheet the other day.
"That is something we can work on in training because it is important to have that strong team shape."
