"Once Ferguson decides you are no longer part of his plans for whatever reasons, there is no turning back,'' Stam said.
"You are like an unwanted piece of baggage and you have to weigh up whether it's worth hanging around when there is no chance of playing."
Speaking to the Sunday Mirror, Stam added: "I think you are just expected to accept it, there is no plan in place if you decide you're not going other than the fact you will probably be left to rot in the reserves.
"I am sure the other players are surprised by Beckham's departure and the way it has happened. I know a lot of them will not want to see him leave.''