Geraint Williams accepts that he will struggle to hang on to his better players during the close season.
The U's are already preparing for life in League One next year, but could see their squad decimated by summer departures.
The likes of 17-goal top scorer Kevin Lisbie, goalkeeper Dean Gerken and player of the year Johnnie Jackson are all likely to have attracted interest from elsewhere.
Williams admits that he is unlikely to be able to keep the trio at Layer Road, especially as the club struggles to compete financially with the sides around them.
"We have to now keep the players I want and that is becoming increasingly hard to do because other clubs in this division have financial resources which we cannot get near," he said.
"I am not confident about keeping the players I want because the club has to be run on an even keel, otherwise you can get into financial difficulty and go right down."