However, they are coming up against a team who were comfortably beaten 3-0 away to German outfit Schalke 04 in their opening fixture of the competition.
Chelsea start the match on the back of Saturday's 1-1 draw at Tottenham Hotspur in the Premier League, while Steaua saw off ACS Poli Timisoara 3-0 in their domestic championship.
The visitors will be without Marco van Ginkel as the Dutch youngster was recently ruled out for the long term with an anterior cruciate ligament injury.
Meanwhile, Mourinho has confirmed that Juan Mata will be in the starting lineup at the Arena Nationala.
Possible starting lineups
Steaua: Tatarusanu; Latovlevici, Szukala, Georgievski, Filip; Gardos, Tanase, Bourceanu, Stanciu; Iancu; Piovaccari
Chelsea: Cech; Ivanovic, Luiz, Terry, Cole; Ramires, Mikel, Lampard, Mata; Hazard; Eto'o
Sports Mole says: 0-2