Ernesto Valverde opts for an attacking, 4-3-3 lineup as he looks to extend Barca's 100% record in Group D, having played a 4-4-2 for the 1-1 draw with Atletico Madrid in the league on Saturday.
In all, there are four changes from the XI that started that game in the Spanish capital, with Ivan Rakitic dropping down to the bench to accommodate Deulofeu's inclusion alongside Lionel Messi and Luis Suarez in the frontline.
Karim Anarifard, who bagged a brace last time out, is absent from the matchday squad altogether, while Diogo Figueiras, Pape Abou Cisse and Saba are also omitted and Kostas Fortounis and Felipe Pardo drop to the bench.
Making up the midfield are Guillaume Gillet, Alaixys Romao, Sasa Zdjelar, Mehdi Carcela-Gonzalez and Thanasis Androutsos, while Omar Elabdellaoui and skipper Alberto Botia come in alongside Dimitris Nikolaou and Leonardo Koutris in the back four.
Barcelona: Ter Stegen; Roberto, Pique, Umtiti, Digne; Paulinho, Busquets, Iniesta; Deulofeu, Suarez, Messi
Subs: Cillessen, Semedo, Rakitic, Denis, Mascherano, Alcacer, Andre Gomes
Olympiacos: Proto; Elabdellaoui, Botia, Nikolau, Koutris; Gillet, Romao, Zdjelar, Carcela-Gonzalez, Androutsos; Odjidja-Ofoe
Subs: Tachtsidis, Fortounis, Durdevic, Vukovic, Kapino, Engels, Pardo
Keep up with all of the action from Camp Nou tonight with Sports Mole's live text commentary here.