The French champions have already secured their place in the next round with minimal fuss and have never lost to Greek opposition, but Wednesday's visitors are in lethal form.Paris Saint-Germain can seal top spot in Champions League Group C with a home win over Olympiakos on Wednesday.
The French champions have won three and drawn one of their four pool games so far - including a 4-1 victory in Greece in the reverse fixture - and sit three points above their midweek opponents and six clear of third-placed Benfica.
Both PSG and Olympiakos top their domestic leagues and are yet to be beaten in their respective title defenses.
Laurent Blanc's side made it 10 victories from 14 Ligue 1 fixtures this term with a comfortable 3-0 win at Reims on Saturday, while its Greek counterparts won their seventh straight Super League game with a 4-1 success over Panthrakikos.
That win extended PSG's undefeated run in all competitions to 34 matches - although they were eliminated on away goals in the 2012-13 Champions League quarterfinals by Barcelona - while Olympiakos is unbeaten in 13 since its loss to les Parisiens in September.
PSG's impressive form both domestically and continentally is in no small part down to the influence of Swedish forward Zlatan Ibrahimovic.
The former Barcelona, AC Milan, Inter and Juventus star has netted 16 goals in 18 appearances this season, with his seven strikes in four Champions League outings putting him behind only Real Madrid's Cristiano Ronaldo (on eight) in the competition's scoring charts.
Olympiakos' Konstantinos Mitroglou, meanwhile, has been in similarly lethal form for his side, scoring 17 in 15 games, including three in four in the Champions League and three of Greece's four goals in uts 4-1 aggregate World Cup playoff success against Romania.
PSG has never lost to Greek opposition - winning seven and drawing one of its eight matches - and is unbeaten at Parc des Princes for 27 matches in all competitions, a streak that goes back to its 2-1 Ligue 1 reverse to Rennes more than a year ago.
However, Olympiakos has won its last two fixtures in France and heads to Paris with an impressive record of its own to defend, having won 15 and drawn two of its previous 17 away fixtures.