The club took the step of releasing a statement saying the Stonebridge Road chief is attracting interest from elsewhere.
McMahon guided the Fleet into the National League a year ago - and in their first season back in the top tier of Non-League football they reached the play-off semi finals.
United chairman Dr Abdulla Al-Humaidi has moved to distance the Irishman from the exit door.
He told Fleet Online that he doesn’t see the situation changing.
“I will not name the clubs involved but Daryl signed a five-year contract last summer and has done a fantastic job at this club,” the owner said.
“I am well aware of how popular Daryl and his style of play is with our supporters.
“I would like to assure them he is totally committed to this club and that his ambition matches ours.”