The Premier League club finished fifth last season and are trying to increase the quality of their squad this summer.
Manager Harry Redknapp said: “There is nothing happening in the transfer market.
“I need to sell four or five players to bring in funds.
“The chairman has made it clear we need to move a few players before we can start doing any business.
“I keep seeing us linked with this player and that, but unless we reduce our squad numbers we will stay quiet in the market.”
