Gibson became an unrestricted free agent Tuesday after his second 10-day contract with the Knicks expired, Keith Smith of Spotrac.com reports.
If the Knicks are interested in retaining Gibson coming out of the All-Star break, he would need to be signed to a rest-of-season contract now that his pair of 10-day deals have lapsed. Though head coach Tom Thibodeau has a long-term working relationship with Gibson and values the 38-year-old as a locker-room presence, the Knicks may not have much of a need for Gibson if starting center Isaiah Hartenstein (Achilles) is ready to play Thursday in Philadelphia.