QPR have agreed a fee with Cardiff for reported Saints target Steven Caulker.

The centre half is also believed to be interesting Liverpool – whose No 1 defensive target is Saints’ Dejan Lovren – and Crystal Palace.

But QPR boss Harry Redknapp is hoping the fact that he has signed Rio Ferdinand will persuade Caulker to return to London.

The 22-year had previously worked alongside Redknapp at Tottenham.

“We've agreed a fee for Steven Caulker, who I like very much,” revealed ex-Saints boss Redknapp.

“I had him at Tottenham as a player and he's done very well. I think for him to come and play with Rio would be a great experience for him.

“I'm looking to play with three central defenders this year. So (there are) those two and then I've got Richard Dunne, Nedum Onuoha, Clint Hill, I've got real good defenders here.”

“For Steven Caulker to come in and be part of it with those experienced players will be great for him.

“Rio will be a big influence on him. For Steven it will be the best education he could ever have in his life to play with Rio."