The visitors travel to the Hungarian capital will a slender advantage after recording a 1-0 win in last week's first leg.
Match preview
Ferencvaros looked set to hold Olympiacos to a goalless draw for the vast majority of the first leg, but their resistance was ultimately broken by Ayoub El Kaabi in the 83rd minute, ensuring that they fell to a narrow defeat in Greece.
With no game at the weekend, Ferencvaros have had a week to reflect upon a result that brought an end to their four-game winning run across all competitions.
Thursday's hosts are still very much in the tie, especially as they have won four of their six home games in the Europa Conference League this season.
However, Dejan Stankovic's side have had to settle for 1-1 draws against Genk and Fiorentina in their last two European home games.
If Ferencvaros can overturn the first-leg deficit, it would represent their first win in a two-legged tie in the main draw of a UEFA competition since they beat Copenhagen on penalties in the 2003-04 season.
Former Sevilla boss Jose Luis Mendilibar has made an encouraging start to his first managerial job outside of Spain after being appointed Olympiacos head coach earlier this month.
After overseeing the 1-0 win over Ferencvaros in his opening match, Mendilibar saw his side claim a comprehensive 4-1 victory over rivals PAOK in Saturday's Greek Super League meeting.
Fran Navarro and Daniel Podence grabbed a goal on either side of a PAOK equaliser, before El Kaabi came off the bench to net a brace and round off a third consecutive victory in all competitions.
Mendilibar's next task will be to get Olympiacos performing on their travels in Europe after the Greek side drew one and lost two of their Europa League group games, which ultimately proved to be a key factor behind their subsequent drop down to the Europa Conference League.
Should the visitors avoid defeat in Budapest, they will seal their place in the last 16 of a European competition for the first time since the 2020-21 Europa League.
Ferencvaros Europa Conference League form:
D
D
D
W
D
L
Ferencvaros form (all competitions):
D
W
W
W
W
L
Olympiacos Europa Conference League form:
W
Olympiacos form (all competitions):
W
W
L
W
W
W
Team News
Stankovic should have the majority of his squad available to him, although he is still without long-term absentee Adam Halmai.
Although his side were narrowly beaten in Greece, Stankovic could decide to select an unchanged lineup for Thursday's second leg.
Ferencvaros forward Barnabas Varga will offer one of the home side's main goal threats, having scored 22 times in 25 competitive appearances this season.
As for the visitors, they are likely to be without the services of Doron Leidner, Gelson Martins and Bandiougou Fadiga.
After making a number of changes at the weekend, Mendilibar could recall Andreas Ntoi, Joao Carvalho and Georgios Masouras.
El Kaabi has scored four goals across his last three appearances, and the forward will be looking to continue his impressive form when he leads the line on Thursday.
Ferencvaros possible starting lineup:
Dibusz; Wingo, Cisse, Mmaee, Ramirez; Makreckis, Maiga; Zachariassen, Abu Fani, Marquinhos; Varga
Olympiacos possible starting lineup:
Paschalakis; Rodinei, Ntoi, Carmo, Ortega; Carvalho, Hezze, Horta; Fortounis, Masouras, El Kaabi
We say: Ferencvaros 1-1 Olympiacos
Like the first leg, we expect Thursday's contest to be a close-fought affair, but we do believe that Olympiacos will protect their slender advantage by holding Ferencvaros to a draw in the Hungarian capital.