The Rome club could slip into the bottom half of the Serie A standings if they lose to their regional rivals, who are battling for top-flight survival.
Match preview
Following a shock 2-1 loss to relegation-threatened Udinese on Monday evening, Maurizio Sarri dramatically decided to hand in his notice to the Lazio board and call time on a mixed spell in the Italian capital.
Less than a week after their second-leg capitulation to Bayern Munich in the Champions League, Sarri stepped down - citing a loss of backing from his players - and his assistant Giovanni Martusciello will occupy the visitors' dugout at Stadio Stirpe.
It remains to be seen whether Martusciello will remain in charge for the last 10 Serie A matches of this season, in addition to a two-legged Coppa Italia semi-final against Juventus, but the ex-Empoli manager now inherits a team in crisis.
Having lost each of their last four games across all competitions, the Biancocelesti are in danger of recording five straight defeats for the first time since 1985, as a previously well-drilled team continue to struggle at both ends of the pitch.
In 2024, no Serie A side has attempted fewer shots than Lazio, while only Sassuolo and Salernitana have faced more shots this year - such a combination has seen them slide further down the league standings.
However, with the chance to make a new start post-Sarri, they now meet a club they have yet to be beaten by in Italy's top flight, having won four out of five previous Serie A meetings with Frosinone.
When these clubs last met, at the very end of last year, not only were Lazio in better shape but so were their opponents: since that time, Frosinone's form has fallen off a cliff.
After a long series of setbacks, the Canarini will now start a matchday inside the bottom three for the very first time this season, having previously made such a promising start to life back in the big time.
Boasting several talented loanees, last year's Serie B champions were in the mix for a top-half place throughout much of the autumn, but after last week's 1-0 defeat to fellow strugglers Sassuolo, they sit one point behind 17th-placed Empoli.
Since mid-December, Frosinone have both won the fewest points - five from 13 games - and conceded more goals than any other side, which is surely a recipe for disaster.
Head coach Eusebio Di Francesco is therefore under pressure to produce results, so after losing to one of his old clubs last time out, the ex-Roma manager and midfielder will be doubly keen to upset Lazio this weekend.
Frosinone Serie A form:
L
L
L
L
D
L
Lazio Serie A form:
W
L
W
L
L
L
Lazio form (all competitions):
L
W
L
L
L
L
Team News
First-choice goalkeeper Ivan Provedel will be missing from Giuseppe Martusciello's first Lazio squad, due to an ankle injury sustained against Udinese, so Christos Mandas is set to make a rare appearance between the posts on Sunday.
While Matteo Guendouzi is back in action after his two-game suspension was reduced - joining Adam Marusic and Luca Pellegrini, who were also sent off against AC Milan earlier this month - fellow midfielder Nicolo Rovella (groin) misses out.
Ciro Immobile and Taty Castellanos battle it out to feature up front: the latter scored Lazio's only headed league goal of the whole season during December's reverse fixture - a 3-1 win for the Rome club - but is more likely to start on the bench.
Meanwhile, Frosinone boss Eusebio Di Francesco has a longer absence list to contend with, as Mateus Lusuardi, Anthony Oyono, Abdou Harroui, Kevin Bonifazi and Riccardo Marchizza are all expected to miss out.
Left-back Emanuele Valeri is also struggling with an ankle problem, so Pol Lirola should step in to the hosts' back four; either Napoli loanee Walid Cheddira or Juventus-owned Kaio Jorge should be supported by top scorer Matias Soule in the final third.
Frosinone possible starting lineup:
Turati; Zortea, Okoli, Romagnoli, Lirola; Brescianini, Barrenechea, Mazzitelli; Soule, Cheddira, Gelli
Lazio possible starting lineup:
Provedel; Lazzari, Gila, Romagnoli, Marusic; Guendouzi, Cataldi, Alberto; Anderson, Immobile, Zaccagni