Mancini pulled a muscle in his left thigh during Roma's 1-0 loss to Reggina in a Serie A match on Sunday and is out for 10 days. Pizarro is not making the trip for family reasons.

Also, defender Philippe Mexes has a calf problem and striker Vincenzo Montella was left off the roster.

Roma did get some good news when Montenegro striker Mirko Vucinic was cleared to play for the first time since his pre-season move from Lecce.

Roma has three points in Group D, which Valencia leads with six points. Olympiakos and Shakhtar Donetsk have one point each.