Les Monegasques eked out a vital 2-1 win over Nantes on Sunday to keep pace with the title-chasing pack, whereas Nice's poor form continued with defeat to Saint-Etienne.
As the most in-form team currently plying their trade in the French top flight, Monaco have now emerged as serious contenders for the Ligue 1 title.
No other side in the division can boast a perfect record from their opening five matches of 2021, with Monaco taking 15 points from a possible 15 since the turn of the year after a wholly inconsistent first half of the season.
Against a struggling Nantes team, defender Guillermo Maripan netted his fourth goal in five matches with the opener before Kevin Volland notched up his 11th of the season in the second half, and Monaco held on for the win over the 10-man Canaris even though Renaud Emond pulled one back in the final 10 minutes.
Having also beaten Lorient, Angers, Montpellier and Marseille in January, Monaco are now just six points off the pace in the race for Ligue 1 glory, and champions Paris Saint-Germain are within touching distance after their shock defeat to Lorient.
However, PSG's superior goal difference means that they are highly unlikely to be overtaken just yet, but goals are Monaco's forte at home, as they have netted at least twice in nine of their 11 league games on familiar territory so far.
Before Nice welcomed Saint-Etienne to the Allianz Riviera at the weekend, Les Verts had only won one of their last 18 matches in the top flight, but they made it two from 19 with a surprise victory over Adrian Ursea's side.
An 88th-minute winner from Charles Abi condemned Nice to their ninth loss of the season as well as extending their winless home run to nine matches across all competitions - with eight of those ending in defeat for Les Aiglons.
Despite their abysmal record on familiar territory, Nice's away record is rather respectable, as they have only lost one of their last eight league matches on the road - keeping clean sheets in five of them - but their recent victory at Lens was down to some individual brilliance from the now-injured Youcef Atal.
However, with just a solitary win to boast from their last seven in the top flight, Nice have slipped to 13th in the table, although they should not be in any danger of being dragged into a relegation dogfight as eight points separate them from the drop zone.
Monaco scraped a 2-1 win on Nice's turf in the reverse fixture on November 8, and Les Monegasques have only suffered one defeat to their opponents on home soil since 2009.
Monaco Ligue 1 form: DWWWWW
Nice Ligue 1 form: DLDLWL
Kovac could elect to name a largely unchanged lineup amid their winning run, but Aleksandr Golovin is pushing for more minutes after numerous substitute outings.
Nice will continue to make do without Atal for another couple of weeks with his hamstring problem, and midfielder Hicham Boudaoui is suspended for this tie.
Monaco possible starting lineup:
Lecomte; Sidibe, Maripan, Badiashile, Henrique; Aguilar, Tchouameni, Fofana, Diop; Ben Yedder, Volland
Nice possible starting lineup:
Benitez; Saliba, Daniliuc, Nsoki; Thuram; Lotomba, Lees Melou, Reine-Adelaide, Kamara; Dolberg, Gouiri
We say: Monaco 3-0 Nice
A meeting with Monaco in their current form would strike fear into the hearts of almost any team right now, and Nice are no exception. The visitors have performed much better on the road than on their own turf so far, but trying to get one over a blistering Monaco outfit will be a bridge too far for Ursea's men, so this should be a straightforward home win.