The Hungarian champions are in the driving seat when it comes to the contest, having recorded a 2-0 victory in the first leg of their second qualifying round contest last week.
Myrto Uzuni and Tokmac Nguen were on the scoresheet in the first leg in Budapest, and the two first-half goals have left Zalgiris with a mountain to climb as they prepare for the reverse fixture on home soil.
The Lithuanian champions were too strong for Northern Ireland's Linfield in the first qualifying round of this season's competition, recording a 5-2 aggregate victory.
Zalgiris have never mentioned to qualify for the group stage of either the Champions League or Europa League, losing to Bodo/Glimt in the second qualifying round of last season's Europa League.
Vladimir Cheburin's side are deep into their domestic season and currently sit first in Lithuania's top flight, having picked up 41 points from their 19 matches, suffering just two defeats in the process.
The Green and Whites have not actually been in league action since the start of the month, which has allowed them to concentrate on Europe, but the team's journey, in the Champions League at least, will come to an end on Tuesday night unless they are able to pull off a famous win.
Ferencvaros, who are 32-time Hungarian champions, competed in the group stages of last season's Champions League alongside Juventus, Barcelona and Dynamo Kiev.
It was always going to be difficult for the Green Eagles to make their mark in Group G, and they ultimately finished bottom of the section, picking up just one point from their six fixtures.
Ferencvaros have placed themselves in a strong position to reach the third qualifying round, but they will also have one eye on their league opener against Kisvarda on July 31.
Peter Stoger's side have not actually lost a competitive match since the end of February, which is an indication of their credentials, and they advanced to this stage of the Champions League courtesy of a 6-1 aggregate success over Prishtina in the first qualifying round.
Ferencvaros' job is far from finished as they prepare to head to Vilnius, but it would be a huge shock if they failed to progress from this position of strength following their two-goal success last week.
Zalgiris, as mentioned, have not been in domestic action since the start of the month, meaning that they have not played since the first leg on July 20, so the players involved should be well-rested.
The home side do not have any confirmed injuries ahead of the clash, but it would not be a surprise to see head coach Cheburin make a couple of changes to his starting side.
Tomislav Kis and Marko Karamarko both came off the bench just before the hour of the first leg, and the two players could now feature in the first XI, but Josip Tadic should keep his spot at centre-forward.
Ferencvaros, meanwhile, also do not have any confirmed absentees ahead of the match, so Stoger could decide to keep faith with the same team that started the first leg.
FK Zalgiris possible starting lineup:
Gertmonas; Mikoliunas, Ljubisavljevic, Tatomirovic, Bopesu; Onazi, Kis, Verbickas; Karamarko, Tadic, Videmont
Ferencvaros possible starting lineup:
Dibusz; Wingo, Blazic, S Mmaee, Civic; Kharatin, Somalia; Nguen; Zubkov, R Mmaee, Uzuni
We say: FK Zalgiris 1-2 Ferencvaros
Zalgiris have left themselves with an awful lot to do in the second leg, and we are finding it incredibly difficult to back against Ferencvaros considering their strength. As a result, we have tipped the visitors to win 2-1 on the night, which would hand them a 4-1 aggregate success in the second qualifying round.