Cardiff will allow long-serving Kevin McNaughton to leave this summer along with Danny Gabbidon and Nicky Maynard.
Highly-rated Atletico Madrid midfielder Saul Niguez has signed a new five-year contract.
Rafa Benitez has revealed that he is in daily discussions with technical director Michael Emenalo over potential Chelsea transfer activity for January.
Chelsea are expected to strengthen their squad next month in a bid to enjoy a successful second half to the season.
Benitez is mulling over which areas of his squad need reinforcing, and expects to draw up a list of targets along with Emenalo after Wednesday's Capital One Cup clash with Leeds United.
"Hopefully we have two or three days after this game where we'll have plenty of time to talk about names," he said.
"There's no formal meeting because we can chat every day. Michael is watching the training session and we talk every day - about players and how the team is doing.
"I know what Michael likes and he knows what I like and we come to an agreement."