The former Inter star is suffering from muscle pain in his thigh and hip.
Moratti told Corriere dello Sport: "It's not a problem. He's a member of the opposing side which is very strong and we know that we'll have to face up to Barcelona with the utmost concentration.
"Ibrahimovic is a champion, but we also have outstanding players. We fear he'll score against us, just as Barca fear Eto'o will score against them. This year, Eto'o hasn't scored in the Champions League, but he usually does in big games and this is one of them."