The first leg ended 0-0 at San Siro, leaving the tie completely in the balance.
"It is a shame that we have to take on this game with so many important absentees," Moratti stressed in today's Press conference.
"Lots of experienced and talented players won't be able to go out there and play.
"The game against Genoa can give us an important boost from a psychological point of view.
"It was a very hard-fought game and it gave us everything we needed to be prepared for Manchester United.
"We are not the team that we were last year and this is a different situation - we just need to play well."