Villa boss Gerard Houllier is understood to be close to agreeing a temporary deal to sign Walker.
The 20-year-old has spent the first half of the campaign on loan at Championship leaders QPR.
Noticed: Walker (left) is on Aston Villa's radar after starring on loan at QPR
He impressed for Sheffield United before making the move to White Hart Lane but the form of Alan Hutton has restricted his first-team chances.
Villa's first-choice right-back Luke Young has been troubled by a knee problem. Youngster Eric Lichaj and Carlos Cuellar, whose preferred role is centre-back, have been used to fill the breach.
Villa assistant manager Gary McAllister said: 'Luke Young has seen a specialist. It is a tough time for him but work is continuing with the physios and doctors trying to get to the crux of the problem.'
Asked if Villa were looking for a right-back, he added: 'We are looking right across the board.
'Anyone who will make Aston Villa better, we are in the market for. As you can imagine, there is a lot of hard work being done in the recruitment area.
'There are a lot of good players here but, at every club, if somebody is available that could make us better, we've got to be able to react.'
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