Dunne limped out of Saturday's 1-1 home draw with Bolton at half-time with a knee injury. The Republic Of Ireland international now faces a race to be available for Wednesday's Carling Cup tie with Blackburn at Villa Park.
Kevin MacDonald, who has been caretaker boss for the opening seven games of the season following the resignation of Martin O'Neill, said: 'Richard got a bang on the knee last Monday and did well to actually play against Bolton.
Injury doubt: Richard Dunne (left) limped off against Bolton after a kick on the knee
Clincher: Ashley Young celebrates making it 6-4 in last season's clash
'It's too early to say whether he'll be fit for Wednesday.'
Winger Stewart Downing suffered a gashed shin against Bolton but is expected to be fit for the third-round encounter - a repeat of last season's epic semi-final between the two clubs that ended 6-4 to Villa.
MacDonald said: 'Stewart has a bad gash on his shin but he's fine.'
Houllier has already met the Villa players but began work in earnest today at Villa's Bodymoor Heath training complex. Villa midfielder Stephen Ireland is optimistic Houllier will bring success to the midlands club.
He said: 'We've met the new manager and everyone is looking forward to the future now.
'Hopefully it is going to be positive. I can't see it being anything but positive. I am sure it is going to be a good decision. Everyone is hungry in the changing room.
'The manager has big plans for us and the players have to get on board.'
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