Emmanuel, who is out of contract, is currently believed to be training with Football League clubs.
Although disappointed to lose such a popular and important player, the club have wished him all the very best for the future.
Although registered for next season, Alex Wall is currently training with new league rivals Sutton United with a view to a permanent transfer ahead of the new season.
A number of triallists featured on Saturday at Dulwich Hamlet as manager Neil Smith continues to shape his squad. These included former West Ham, Leyton Orient and England Youth international winger Blair Turgott, 21-year-old ex-Crystal Palace midfielders Connor Dymond and Will Hoare.