Former Dolphins guard Richie Incognito has said he wants to return to the NFL and Ian Rapoport of NFL Network says he can indeed sign a contract under certain circumstances.
Richie Incognito wants to return to @NFL . What is his status? Source says he CAN sign a contract, but cannot be paid or play until… (1/2)
— Ian Rapoport (@RapSheet) March 21, 2014 
(2/2) … Incognito undergoes comprehensive eval by NFL-NFLPA designated medical advisors. Goodell must review their report & recommendation.
— Ian Rapoport (@RapSheet) March 21, 2014