The man who left Fratton Park this summer for Field Mill has been disciplined for an ‘alleged serious breach of club discipline’ along with team-mate Jacob Mellis.
Mansfield stated neither player is available for training or selection for games and they have launched an investigation after taking action.
Donohue made 50 appearances for Pompey after arriving from Chesterfield in 2017, before departing as his contract came to a close at the end of June.