The newly-promoted side, meanwhile, are still searching for their first win of the season after taking only one point from their opening four matches.
Match preview
Montpellier have had an eventful start to the Ligue 1 season, with their four matches yielding 22 goals across two victories and two defeats.
After beginning the campaign with a 3-2 home win over Troyes, Wednesday's hosts went on to lose 5-2 and 2-1 to Paris Saint-Germain and Auxerre respectively.
However, they bounced back from consecutive defeats in emphatic fashion as they hammered Brest 7-0 on Sunday to claim their first away win of the season.
Elye Wahi and Valere Germain both netted braces in the comprehensive victory, while Faitout Maouassa, Wahbi Khazri and Nicolas Cozza also got on the scoresheet.
Sitting in eighth place ahead of the midweek encounter, Olivier Dall'Oglio's side will now look to record consecutive victories for the first time this season.
The visitors, meanwhile, are winless in their opening four games after winning promotion from Ligue 2 last season.
They began the campaign with a narrow 2-1 defeat away to Lyon before they picked up their sole point courtesy of a goalless draw against Lens.
However, they were unable to build upon that point as they lost 2-1 Rennes, ensuring they begin the season with consecutive away defeats.
A return to home surroundings at the weekend did little to change their fortunes, with a late strike from Cyrille Bayala not enough to prevent his side from losing 3-1 to Lille.
Having conceded at least twice in three of their four matches this term, Ajaccio need to improve defensively if they are to move off the bottom of the Ligue 1 table.
Montpellier HSC Ligue 1 form:
Ajaccio Ligue 1 form:
Team News
Montpellier has a number of injury concerns, with Dimitry Bertaud, Mamadou Sakho, Pedro Mendes expected to be absent, while Stephy Mavididi and Sacha Delaye are doubts for the midweek contest.
Teji Savanier is still suspended for the hosts, although Khalil Fayad could return to the squad after serving a one-match suspension.
Despite coming off the bench to score a brace against Brest, Germain will have to settle for a place on the bench, with Dall'Oglio set to name an unchanged lineup.
As for the visitors, they are unable to call upon Mounaim El Idrissy, who is suspended for Wednesday's encounter.
After coming off the bench in the second half against Lille, Riad Nouri is in contention to be given a starting place.
Bevic Moussiti-Boko was also a substitute in the weekend contest, and the 27-year-old could come into the side to partner Romain Hamouma in the frontline.
Montpellier HSC possible starting lineup:
Omlin; Sacko, Jullien, Cozza, Sainte-Luce; Chotard, Ferri; Nordin, Khazri, Maouassa; Wahi
Ajaccio possible starting lineup:
Leroy; Alphonse, Mayembo, Gonzalez, Diallo; Nouri, Marchetti, Mangani, Bayala; Moussiti-Oko, Hamouma