Sunderland manager Gus Poyet has admitted that his side's goal return could become a concern soon.
The Black Cats played out their second Premier League goalless draw in succession on Saturday against Swansea City at the Stadium of Light.
Poyet has admitted that the team are missing Fabio Borini, who impressed while on loan from Liverpool last season.
"I think in the last year, that's why we've played with a 4-3-3," Poyet told the Sunderland Echo.
"One winger and the other two were the strikers, because Fabio was doing a terrific job on the left, but he was playing as a striker. We haven't found that formula yet.
"Now we've got more wingers than before. We're trying to look for the formula that's going to work and then you need to get a break."
Sunderland sit 16th in the table following the draw.
