Although the visitors hold a 3-2 lead on aggregate, the momentum is with the home side after their stirring fightback in Greece last week.
Match preview
Even having put together some of their best domestic form in recent memory, Fenerbahce face the prospect of ending the season without silverware unless luck goes their way.
Ismail Kartal's side sit two points adrift of leaders Galatasaray in Super Lig, despite collecting 85 points from 32 matches, and the title race could hinge on their head-to-head on the penultimate matchday, with Galatasaray the hosts on that occasion.
For now, though, Kartal will be focused on trying to extend their run in the Europa Conference League, particularly given the resilience that was shown at the Karaiskakis Stadium last week.
Fenerbahce found themselves 3-0 down after 57 minutes, facing the real prospect of the second leg barely being competitive, yet they were back to within one goal 17 minutes later.
Incredibly, Fenerbahce have now lost four of their last six European fixtures this season, yet they are potentially a home win away from setting up a showdown with either Aston Villa or Lille.
On the flip side, Olympiacos make the trip to the Şukru Saracoglu Stadium knowing that they will reach a first semi-final in UEFA competition in their history.
Olympiacos dropped into this competition on the back of finishing third behind West Ham United and Freiburg in their Europa League group, but they have managed to take advantage thus far.
Four wins and 12 goals have come from their five fixtures since February, Jose Luis Mendilibar's side having recorded 1-0 and 6-1 away wins over Ferencvaros and Maccabi Tel Aviv respectively.
Their domestic efforts have not been as impressive, with Mendilibar's side sitting six points adrift of the leaders in fourth position, albeit with a game in hand.
Nevertheless, unlike their hosts, they had the weekend off from domestic action, and it remains to be seen whether the extra rest could play its part.
Fenerbahce Europa Conference League form:
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Fenerbahce form (all competitions):
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Olympiacos Europa Conference League form:
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Olympiacos form (all competitions):
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Team News
Ferdi Kadioglu is expected to come into the Fenerbahce XI after Jayden Oosterwolde would forced off injured in the first leg.
Rodrigo Becao suffered the same fate later in the game, but the centre-back was able to take his spot on the substitutes' bench three days later.
Fred was only named among the replacements in Greece, although the Brazil international should start here.
With Mendilibar having shown preference for a 4-4-2 of late, it would come as little surprise if he selected a similar Olympiacos starting lineup.
However, Panagiotis Retsos is suspended after collecting his third yellow card and could be replaced by Andreas Ndoj given a number of other centre-backs who are absent through injury.
Vicente Iborra and Andre Horta are both alternatives if he wishes to bring a third midfielder into his team.
Fenerbahce possible starting lineup:
Livakovic; Osayi-Samuel, Becao, Soyuncu, Kadioglu; Fred, Krunic; Kahveci, Szymanski, Tadic; Dzeko
Olympiacos possible starting lineup:
Tzolakis; Rodinei, Ndoj, Carmo, Ortega; Masouras, Chiquinho, Hezze, Fortounis; El Kaabi, Jovetic
We say: Fenerbahce 2-2 Olympiacos (Olmypiacos to win 5-4 on aggregate)
Judging by last week's contest, we can only predict goals for the reverse fixture. Fenerbahce will back themselves on home territory, yet we cannot see how they manage to keep their opponents out for the 90 minutes. With that in mind, we are backing a score draw, leading to Olympiacos progressing through to the last four.