Paulinho starts ahead of the Croatia midfielder in the engine room, alongside Sergio Busquets and Andres Iniesta.
Rakitic's absence gives him a much-needed rest, after being almost ever-present for Barcelona and Croatia so far in 2017-18.
Ernesto Valverde is also without Jordi Alba, out with a muscle complaint, meaning Lucas Digne fills in at left-back.
Barca are otherwise at near full-strength for the visit of Olympiakos, with Lionel Messi and Luis Suarez starting after a strenuous past week with club and country.
There is no room, however, for Nelson Semedo, as Sergi Roberto gets the nod from Valverde to start on the right side of defence.
Barcelona: Ter Stegen; Roberto, Pique, Umtiti, Digne; Paulinho, Busquets, Iniesta; Messi, Suarez, Deulofeu.
Substitutes: Cillessen, Semedo, Rakitic, Denis, Mascherano, Alcacer, Andre Gomes
Olympiakos: Proto; Elabdellaoui, Botia, Nikolaou, Koutris; Gillet, Romao, Zdjelar; Carcela-Gonzalez, Odjidja, Androutsos.