A late bid from Aston Villa for Tottenham's Younes Kaboul may have thwarted Roy Keane's efforts to bring the defender to Wearside.

The Spurs player was due to arrive at Sunderland for a medical today but reports this morning claim he has asked Keane for more time after a bid came in from Villa last night.

Keane has already signed Teemu Tainio from Spurs and Republic of Ireland goalkeeper Nick Colgan this week.

Tainio and Kaboul are one half of a Spurs quartet which Sunderland have offered €29million for.

Paschal Chimbonda appears to be on the verge of signing after completing his medical with Tainio, while Keane holds out hope of landing Steed Malbranque, despite the Frenchman's silence on the subject.

Keane met the 22-year-old Kaboul last Saturday despite his agent, Rudy Raba, insisting there was no chance of the player joining Sunderland.

However, the former Auxerre man later revealed he was hugely impressed with what the Irishman had to say, and has since spoken warmly about the prospect of resuming his career at the Stadium of Light.

But despite his problems in establishing himself at White Hart Lane following his move last summer, there have been other interested parties.

Portsmouth boss Harry Redknapp admitted his club was in the frame last week, but later revealed he understood the defender would be joining Villa.

But Sunderland's proactive approach seemed certain to pay dividends when Raba revealed on Tuesday he expected his client to make a decision within 24 hours.

However, he is now understood to have asked the Black Cats for another 24 hours, and with Villa now stepping up their pursuit, the deal could be in the balance.