Houllier has been encouraged by the youngsters who have filled the breach when up to a dozen players have been sidelined through illness or suspension.
But the former Liverpool boss is aware Villa have dropped 12 points in matches where they have been ahead during the current campaign.
This was highlighted a fortnight ago when Villa led Manchester United 2-0 after an exhilarating second half performance but ended up drawing 2-2.
Houllier said: "I'm confident, I trust this lot of players.
"But we have dropped 12 points from leading positions. That is a fact whether it was against Stoke, Bolton, Tottenham, Fulham or Manchester United.
"That is where we need to improve, definitely, in terms of maturity because being in a leading position to win, even if you drop half of those 12 points, we would now be on 23 points.
"I still think this is an area we have to address. Maybe this is the right time to stop that."
Houllier has immense respect for Gunners boss and close friend Arsene Wenger but wants to get one over on his fellow Frenchman.
He said: "Whatever happens on the field, we will remain friends. You have to give respect to what he has achieved at Arsenal in nearly 15 years.
"He had the team of the old type with Dixon, Adams, Winterburn and so forth.
"From that team, he gradually moved to a different team but kept the entertaining side.
"At a high level, you've got to win and he is a winner. You need to win in style and entertain. No-one will argue with that.
"He will have left a legacy when he leaves the club in terms of a new stadium, new facilities, a squad for the future, so I have got a lot of respect for that.
"But he has been a friend for nearly 30 years. We took our coaching badges together, went to tournaments together, we laugh together but I'd love to beat him and he knows that."
Striker Gabriel Agbonlahor is battling to be fit for the game.
Agbonlahor has missed training for the past two days through illness and his condition will be assessed during the next 24 hours. Fellow striker John Carew is available after a four-game absence due to a calf problem.
Houllier confirmed defender James Collins will play after he missed the 2-0 defeat at Blackburn, also with a calf injury. Young midfielder Jonathan Hogg is Villa's only new injury doubt after suffering an ankle injury at Ewood Park. Robert Pires will be included in the 18 to face his former club.
Meanwhile, Wenger has revealed his surprise at Houllier's return to frontline management.
Wenger said of Houllier's return: "I wasn't surprised that Aston Villa took him but I was surprised - because he was in a position as director of the French Football Federation - that he chose to leave his job and come again into a hotseat after what he has gone through."
While he may have been taken aback by Houllier's Villa move, Wenger was not surprised to see his friend bring Pires to the midlands club last week.
Pires had been training with former side Arsenal after being released by Villarreal in the summer and despite not re-signing the 37-year-old himself, Wenger was in no doubt he could still do a job in the Premier League.
"I saw what he has been doing in training," he said.
"He is the type of player who can help any team in the Premier League, just at that age it is important you use him well at the right moment, but I am not surprised that Gerard Houllier thought about him."
Asked how he would greet Pires at Villa Park, Wenger joked: "Well, 'Happy to see you and be quiet today!"'
Cesc Fabregas will miss out after being ruled out for an estimated two weeks with a hamstring strain.
Fellow midfielder Emmanuel Eboue is out for up to eight weeks with a knee ligament strain, strikers Robin van Persie and Andrey Arshavin come back into the squad after being rested for Tuesday night's Champions League game at Braga, while defender Gael Clichy could shake off a back problem.
Goalkeeper Manuel Almunia (elbow) may return, but centre-half Thomas Vermaelen (Achilles) and midfielder Abou Diaby (ankle) remain out, while Aaron Ramsey has joined Nottingham Forest on loan.