Wednesday night's FA Cup replay against Plymouth will be the penultimate game before Simpson is due to return to Manchester United.
Chris Hughton: "Any conversations between ourselves and Manchester United remain private.
"West Brom is Danny's last game. He has done very well and it is something we are working on.
"It is one of the areas we have consistently said we want to bring players in. Right-back, centre-back and centre-forward.
"Not necessarily different players, all the players we have brought in on loan have done very well.
"In Ryan Taylor we also have a player who has played a lot of games at right-back and some people think that is his best position."