Sheffield United boss Bryan Robson has revealed Sunderland are watching Aston Villa defender Gary Cahill and Manchester United fullback Phil Bardsley - both of whom have been on-loan at Bramall Lane.

"Roy (Keane) has been at a few of our games recently, maybe watching Cahill and Bardsley," Robson told the club's official website.

"In relation to Cahill, all we can do is wait for (Villa manager) Martin O'Neill to make his decision.

"I would love to keep him until the end of the season but O'Neill will know he can't replace Gary on the cheap."