The Nerazzurri skipper ruptured his left Achilles tendon during his side's 1-0 loss against Palermo at the weekend and faces a lengthy spell on the sidelines as a result.
Nevertheless, Moratti does not think that his injury problems will force the 39-year-old to end his playing career.
"It's very sad, I feel really bad for him and he knows that. I spoke to him straight after it happened. But with his character he'll be back, no doubt about it," he was quoted as saying on the official Inter website.
"The fans cannot think they will not see him back playing at his usual his best. I have no doubts that he will be back playing at his usual high level."
Zanetti has made 48 appearances in all competitions for Inter this term.