Manchester United manager Sir Alex Ferguson has handed starts to the experienced quartet of Ryan Giggs, Park Ji-Sung, Michael Carrick and Darren Fletcher.
Anders Lindegaard has also taken the place of David de Gea in goal, while Chris Smalling partners Jonny Evans in central defence.
For hosts Benfica Pablo Aimar will play in an attacking midfield role, with Belgian international Alex Witsel in support of Oscar Cardozo.
Benfica: Artur; Emerson, Luisao, Maxi Pereira, Garay; Amorim, García, Aimar, Gaitán, Witsel; Cardozo.
Man Utd: Lindegaard; Fabio, Smalling, Evans, Evra; Giggs, Fletcher, Carrick, Park, Valencia; Rooney.
