Cook (shoulder) is working on the side field at practice Thursday, Rich Cimini of ESPN.com reports.
Cook may soon leave team facilities and fly home to South Florida for the birth of his first child, but he would then rejoin the Jets shortly. The veteran running back has been busy in meetings and observing practice since officially signing with New York on Monday, but rehab from offseason surgery has prevented Cook from participating in on-field activities yet. Meanwhile, Breece Hall (knee) came off the PUP list Tuesday and is being eased into action.