Bids are said to have been made for several players this week but all have been rebuffed.
"I said earlier this month that our first-team players would still be here next month and I completely stand by that," Ridsdale told the Western Mail.
"The board has taken the view we must keep our squad together now that gives us the chance to see where that leaves us at the end of the season.
"If anybody were to come in with a 'killer' offer for one of our players now we would not sell. We are holding on to our players.
"The decision has been made that the January transfer window is not the right time for us to sell players."
City have already sold Chris Gunter to Spurs, Steve MacLean to Plymouth and Jason Byrne to Bohemians of Dublin. Gunter was a bad loss (even though we got money for him we could have done without losing a teenage Welsh international). Byrne a good loss, he just didn't look like ever making it. MacLean was good business, brought in on a free and sold for half a million 6 months later. His departure depleted the squad though leaving short of fit strikers.
So far only keeper Peter Enckleman has come in. He is on loan for the rest of the season.
City can loan more players when the emergency loan window opens next week and runs through until late March.