Both southern giants will be targeting a place in the Coppa quarter-finals, ahead of Sunday's league meeting in Naples.
Match preview
Three days after Lazio's long winning run finally ended with last week's Europa League draw against Ludogorets, the Rome club then suffered their first defeat since mid-October.
Picked off by Parma at Stadio Tardini, Marco Baroni's men had two goals chalked off and a penalty overturned, with Taty Castellanos scoring their only goal in a 3-1 loss that halted their streak of five straight Serie A victories.
Nonetheless, they are among the chasing pack behind leaders Napoli, who they trail by just four points, and could yet mount a challenge for the Scudetto in an apparently wide-open title race.
Though their previously flawless Europa League record has been blotted, the Biancocelesti are also top of the pile in UEFA's second-tier competition and firmly on course for a place in the last 16.
Therefore, Baroni can lead Lazio into Thursday's clash with confidence; particularly as the seven-time Coppa Italia winners have won two of their last three meetings with Napoli and drawn the other.
While their hosts were given a bye to this stage of the Coppa, six-time winners Napoli had to make their way through two earlier rounds in order to reach the last 16, as a result of failing to qualify for European competition.
After edging past Modena on penalties in Antonio Conte's first competitive match as head coach, the Partenopei swept Palermo aside in October, winning 5-0 in their round-two tie, with Scott McTominay netting the final goal at Stadio Maradona.
Their Scottish star was on target again at the weekend, when Napoli continued their quest to regain the title by beating Torino 1-0; making it back-to-back wins since a minor wobble before the international break.
The Campanian club had taken only one point from encounters with Atalanta BC and reigning champions Inter Milan - both of whom are on their coat-tails near a packed Serie A summit - but they are still on top after 14 rounds.
Following their latest success, Conte's side have also kept nine clean sheets in the league this term - plus two in the Coppa so far - and they now aim to shut out free-scoring Lazio.
Lazio form (all competitions):
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Napoli Coppa Italia form:
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Napoli form (all competitions):
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Team News
Joining left-back Nuno Tavares on the sidelines, Lazio midfielder Matias Vecino will be out of action for at least another week, and Gaetano Castovilli is still recovering from knee surgery.
Marco Baroni's options may be further restricted by an ankle problem for Boulaye Dia, who has been an effective foil for top scorer Taty Castellanos since signing in the summer.
As in the Europa League, Baroni should make a number of changes to his lineup this Thursday, with Pedro, Samuel Gigot and cup goalkeeper Christos Mandas all likely to come in.
Meanwhile, Antonio Conte has suggested he will engage in some rotation in preparation for the teams' league fixture on Sunday - and even hinted at a potential switch of formation.
Particularly focusing on the need to offer Italy forward Giacomo Raspadori more minutes, the Napoli coach also noted that - aside from the injured Pasquale Mazzocchi - his full squad should be available.
Regular starters such as Romelu Lukaku, Scott McTominay and Khvicha Kvaratskhelia could all be rested, as the likes of Raspadori, David Neres and Leonardo Spinazzola get a chance to shine instead.
Lazio possible starting lineup:
Mandas; Marusic, Gigot, Patric, Pellegrini; Rovella, Guendouzi; Tchaouna, Pedro, Noslin; Castellanos
Napoli possible starting lineup:
Caprile; Di Lorenzo, Marin, Jesus, Spinazzola; Folorunsho, Gilmour; Neres, Raspadori, Ngonge; Simeone
We say: Lazio 2-1 Napoli
Although Napoli have proven so hard to beat this season, they will have more than one eye on Sunday's game and could become Lazio's latest victims at the Olimpico.
Written by
Jonathan O'Shea