Not only does Fitzgerald have $9 million to play with, Hamilton's return timeline comes at a perfect time. With that much money, Fitzgerald could add a couple of players if he wanted, and still be able to have them, and Hamilton, participate in the playoffs where the cap rules are far more relaxed.
Hamilton tore a pectoral muscle in a game against the New York Islanders at the end of November. New Jersey is outside of a playoff spot at the moment, but not by much, and there's plenty of time to go.