Luiz and Mikel missed Saturday’s 1-0 win over Everton through injury, while Oscar was substituted at half time because of an ankle complaint.
Mourinho is able to call on the trio for the first leg encounter with Roberto Mancini’s Galatasaray in Istanbul though after the club revealed they have travelled to Istanbul.
|12/1||Chelsea are 12/1 with William Hill to win the Champions League this season|
The Blues face the Turkish Super League champions in the Turk Telecom Arena on Wednesday night but will be without January signings Nemanja Matic and Mohammed Salah, who are both ineligible having featured in the tournament with their former clubs earlier this season.
Chelsea topped their group, pipping Schalke to top spot with a record of four wins and two defeats from their six games.
Galatasaray meanwhile, sneaked into the knockout phase, eliminating Juventus by defeating the Italian champions 1-0 in the final group game.
Mancini can call upon former Chelsea legend Didier Drogba, as well as Wesley Sneijder for the first leg contest.
Full squad: Petr Cech, Mark Schwarzer, Henrique Hilario; John Terry, Gary Cahill, David Luiz, Ashley Cole, Cesar Azpilicueta, Branislav Ivanovic, Tomas Kalas; Nathan Ake, Frank Lampard, John Mikel Obi, Ramires, Oscar, Eden Hazard, Andre Schurrle, Willian; Fernando Torres, Samuel Eto'o, Demba Ba.