The 4-1 home thrashing means Italy will now go into the World Cup playoff draw for a place in next summer's tournament.
Frattesi said, : "When you lose 4-1, it's difficult to explain the match, you clearly have to apologise.
"But it's a product of the path we've taken in this qualifying group; we haven't shown we're the Italy everyone knows.
"Italy has always been a team that wins 4 or 5-0 against lesser-known opponents. That wasn't the case, so it's a product of this path that needs to be straightened out in every way."
He also stated: "If the defence has some problems... it's a sign of a problem. It means that perhaps the attackers pressed poorly, the midfielders didn't filter the ball."