Sheridan nodded an early second-half header wide of the mark but the on-loan Celtic striker grabbed Motherwell's second in the 58th minute with a simple goal from close range after a StevenHughes crossed broke into his path.
Striker Steven Fletcher departed Hibs to join Burnley this week and Hughes has been linked with moves for Rangers' Alan Gow and Sunderland's Anthony Stokes, the forwards he worked with at Falkirk.