The veteran midfielder was only a substitute in the first leg but features from the off at Stamford Bridge, with Branislav Ivanovic back in defense for Roberto Di Matteo.
The veteran midfielder had been included from the off in the Blues' Premier League win over Aston Villa on Saturday but was left on the bench in the first leg of the European clash. Raul Meireles was preferred on that occasion, but is a substitute this time.
Branislav Ivanovic, who scored twice at the weekend, continues at right-back in place of Paulo Ferreira, who was preferred for the first leg in Portugal.
Benfica coach Jorge Jesus also makes two changes from the first leg - defensive midfielder Javi Garcia becomes an emergency center back due to the absences of Luisao and Jardel.
Left back Joan Capdevila, a World Cup winner with Spain in 2010 but frozen out since his arrival in Portugal, is recalled for the game at Stamford Bridge, with former Chelsea midfielder Nemanja Matic stepping up from his substitute role in the first leg to start the second.
Star strikers Fernando Torres and Oscar Cardozo both lead their respective lines, the Spaniard having finally scored his first Premier League goal in six months against Villa.
Chelsea starting XI: Cech; Ivanovic, Luiz, Terry, Cole; Mikel, Lampard; Ramires, Mata, Kalou; Torres
Subs: Turnbull, Ferreira, Cahill, Essien, Meireles, Sturridge, Drogba
Benfica starting XI: Artur; Pereira, Garcia, Emerson, Capdevila; Gaitan, Matic, Witsel, Cesar; Aimar; Cardozo
Subs: Eduardo, Almeida, Nolito, Djalo, Oliveira, Rodrigo, Saviola