Hughes had been released by the Saints on Monday to clear space for the addition of tackle Bryce Harris off waivers from the San Francisco 49ers.
The Saints felt they were able to part with Greco with guard Larry Warford returning to practice from an abdominal injury on Wednesday. Warford had been inactive the last two games for New Orleans. Greco will have to go through waivers before becoming a free agent. He was not active for any game with the Saints this season.
Hughes has played in one game this season for the Saints, recording a tackle against the Chicago Bears two weeks ago.