Newcastle boss Alan Pardew believes the vast majority of managers must be on their guard during the January transfer window.
Pardew saw star striker Andy Carroll leave Tyneside last January when Liverpool finally broke the Magpies' resolve to hang on to him with a cheque for £35million.
The Newcastle boss is gearing up for a battle to hang on to similarly coveted midfielder Cheick Tiote this time around, while skipper Fabricio Coloccini and fellow defender Danny Simpson are yet to sign new contracts.
Pardew believes every manager cannot relax during the January transfer window, except Manchester City's Roberto Mancini and Manchester United's Sir Alex Ferguson.
Asked if any manager could say a player was simply not for sale, the Newcastle boss said: "I should think Mancini could probably say that and possibly Alex Ferguson, but no-one else.
"I hate the window. All managers, whether you are in the second division and you are losing a player to the first, or you have a top first division striker and you lose him to the Championship, we are all the same.
"We could lose our players to the Champions League teams, so you are all on your guard.
"Players start manoeuvring and agents - it's not a very nice period."