Reading keeper Adam Federici is concerned that a January spending spree could disrupt team spirit.
Russian owner Anton Zingarevich hinted last week that he may bring in up to 10 new players in January.
"We've been together as a good squad for a long time now," the Australian said. "We have added a few players but I think there is a danger when you add too many players into a squad - you kind of break that team spirit.
"It's something we have here in abundance. You have to be careful who you bring in, the sort of characters that come in. It's alright for people who sit far away from the game and say, 'I want that player and that player'.
"But you need to look at their personalities and think, 'Are they going to fit into the group' before bringing in any players."