Fed can do it. How much does he want it and how much will he try to get his game going again is the question.
Couple of things here.
Fed knows that the chances are dwindling so might push extra hard.
He's had some time to rest, got rid of the larger racket and has had plenty of family time.
He has pride, the same pride that pushed him for so many years.
Call it vanity but none the less it is a powerful motivator for some, I think Fed fits the bill here for that.