Gus Poyet has told the Sunderland Echo that his side are unable to play with a system which includes three centre-backs.
The Uruguayan says that he does not feel comfortable coaching a team which doesn't operate with a back-four and he's not convinced Sunderland have the players to adapt to it successfully.
Poyet believes Sunderland's options at full-back are too defensive to be given more attacking roles and he says that he won't utilise a 3-5-2 again this season.
“It’s not me," he said. "I’ve been four at the back all my life and I will stay like that. Nobody has won the Premier League with three at the back ever, but I think Liverpool have done very well changing to three. Maybe because of the personnel.
“Us, I wasn’t really convinced what the wing-backs really give you in that system. They need to be more offensive than defensive, more wingers than full-backs. We didn’t find that situation right.”
Sunderland actually tried the system earlier in the campaign, but Poyet is clearly not interested in using it again, even if he does want to get two strikers on the pitch.
The Black Cats had appeared happy to operate with a functional and defensive 4-1-4-1 formation in the early part of the campaign, but Jermain Defoe's arrival has complicated things.
The England international is not cut out for playing as a lone striker, but Poyet still has not been able to devise an effective strategy which gives him a partner up-front.
Defoe still has managed two goals in his seven appearances for the North East outfit, but he hasn't been able to increase their attacking threat enough to fire them away from the drop zone.
At the moment Sunderland are just three points clear of the relegation spots and if Poyet cannot find a system which suits his players soon then there could be dire consequences in May.