After a turbulent few weeks, both personally and professionally, Rooney showed admirable composure to stroke home the 87th-minute penalty that gave United their 1-0 Champions League win over Rangers.
The goal swept the Red Devils into the knockout stages with a game to spare, but almost as importantly it signalled Rooney's well-being following a debilitating ankle injury and the furore over his new contract.
Typically, Rooney feels he is back to top form. Ferguson is more cautious.
"He needs games," said Ferguson. "The way we are going to do that is to keep him on the pitch for 90 minutes.
"That will continue now as we try to get him to his level. He is rusty, that is obvious, but it is a start for him."