For Napoli, a team that always inhabits the top four, this season has been one of reckoning - a period in which the club has had to make a painful reappraisal of where they are going.
Marooned in eighth spot in Serie A, Napoli have not just failed to claim consistent results but indeed been unable to locate any sense of attacking rhythm on the pitch.
Following the days of Maurizio Sarri, during which the Naples side played with a highly discernible tactical approach, the period under Ancelotti held witness to a number of directionless displays, with players looking stunted and attacking patterns nowhere to be seen.
Indeed, that Napoli have only won three times at home in Serie A all season indicates that this team does not have any clear blueprint on which to rely when opponents sit back and soak up pressure.
As they prepare to face the league leaders, Gattuso and his players will know that victory would galvanise not just their spirit but also provide a much-needed foundation to build from going forward.
In Inter, however, Napoli come up against a side playing with a real sense of confidence and swagger under Antonio Conte, who has given this team a clear backbone.
Playing with his classic three-at-the-back system, Inter have become a side capable of keeping possession as well as springing opponents in key areas of the pitch.
More pertinently, perhaps, Conte has engendered a feeling of fearlessness among these players, allowing them to believe that Juventus - so untouchable in recent years - can indeed be challenged at the top of the table.
Crucial to this attitude has been the strike partnership of Romelu Lukaku and Lautaro Martinez, who have netted a combined total of 20 league goals this term and added definition to attacking movements.
A win in Naples, where Inter have not won in Serie A for well over a decade, would only add to the club's belief that they really can win their first Scudetto since 2010.
Napoli Serie A form: DDLDLW
Napoli form (all competitions): DLDWLW
Inter Milan competition form: WWWDDW
Inter Milan (all competitions): WWDLDW
Napoli possible starting lineup:
Meret; Di Lorenzo, Manolas, Hysaj, Rui; Elmas, Allan, Zielinski; Insigne, Callejon, Mertens
Inter Milan possible starting lineup:
Handanovic; Bastoni, De Vrij, Skriniar; Candreva, Valero, Brozovic, Vecino, Biraghi; Martinez, Lukaku
We say: Napoli 1-2 Inter Milan
Having claimed their first win under Gattuso prior to the winter break, Napoli will come into this game with furious intensity, but the gulf in confidence - especially in the final third - between the two sides may ultimately prove to be decisive.