Free agency is 5 1/2 weeks away, but Jeremy Lin’s agent already is setting the groundwork for what could be a complicated negotiation.

Roger Montgomery, in a rare interview, told The Post nothing is assured regarding Lin’s Knicks future, despite interim coach Mike Woodson’s declaration the global phenom — who becomes a restricted free agent on July 1 — would “absolutely’’ return.

When asked if he expects the Knicks negotiation to be cut-and-dried, Montgomery forewarned: “I don’t expect that. We’re not anticipating that’s going to happen. We don’t have assurances of anything. I know history shows most restricted free agents go back to their team, but I’m not going to assume anything. We’re waiting to see what happens.’’

via Marc Berman of the New York Post