Fonseca was speaking ahead of their clash with Empoli.
He stated, “We were more organised against Juve, we were better in transition against Slovan.
“It seems like when we improve on something, other problems crop up. Just because you win doesn’t mean that we can close our eyes and pretend everything is fine. We have to look at the problems.
“Problems arise game by game. We were well disciplined and worked hard against Juve, while we were a better team in transition in Bratislava. We’ve always spoken about defensive problems, but we have the fifth best defence in the league. We’ve conceded the same as Inter and Lazio.
“In Italy, you need to have two faces in attack. We had one against Juve and Slovan, we need another when we face Empoli and Atalanta.”