Houllier will not be in charge for Monday night's Barclays Premier League clash at Stoke as he ties up the loose ends with the French Football Federation after resigning as their technical director.
Caretaker boss Kevin MacDonald will select the side for a sixth successive match before Houllier takes control during the next couple of weeks.
Downing said: "I saw his (Houllier's) press conference on TV when it got announced that he was the new manager and he came across very well.
"If you look at his past record as a manager, with what he did at Liverpool and at Lyon, he's obviously got a good record and you don't get jobs like that if you're not very good.
"There's no reason that I can think of why he can't do very well at Aston Villa. He's got a good squad of players to work with. It's a great club, great facilities, so everything's in place for him to do very well. I'm sure he's excited to come and work with the squad because, if he looks at it, he's got some very good players on his hands here."