Ibrahimovic was sent off when PSG lost at home to Saint-Etienne, and in wo games without their talismanic striker they were held at Montpellier and lost at the Parc des Princes to Stade Rennes.
Ibrahimovic set up five of his team's six Champions League goals in wins over Dinamo Zagreb and Dynamo Kiev, and his absence from domestic duty was keenly felt by PSG.
"Without Ibra, who is Ballon d'Or material like Messi or Ronaldo, it is inevitably different," sports director Leonardo told reporters.
Coach Carlo Ancelotti should also be able to rely on Lavezzi, who had struggled with injuries and lacked fitness before finally delivering on Wednesday, scoring both goals against Dynamo.
Ibrahimovic sometimes takes up deep positions to draw defenders towards him, leaving space in front for Lavezzi, who then uses his devastating speed.
"For the first time since he is at PSG, he was the Lavezzi everybody knows," Ancelotti told reporters.
"He played a great game [against Dynamo], he scored.
"Unfortunately he was late in his preparation because of his injuries in the early season. But I see a better future for him."
PSG are third in the league with 23 points from 13 matches, two points adrift of leaders Olympique Lyon, who travel to Toulouse on Sunday and have a game in hand.
PSG have spent over 200 million euros in transfer fees since being taken over by Qatar Sports Investments (QSI) last year and third place is not good enough.
"Carlo [Ancelotti] is used to crisis situations," Leonardo said. "He is not going to cry over it. Our problem is a lack of concentration through time."
Ibrahimovic does not seem too concerned either.
"The coach talked about a crisis? I don't know, I have not been around lately. You know, the club is growing everyday into an important club and it's normal that we are under permanent pressure," he said.
Fifth-placed Saint-Etienne, who trail Lyon by three points, will leapfrog their arch rivals if they beat sixth-placed Valenciennes on Friday.
The match features the top two attacks in the league - Saint-Etienne have scored 23 and Valenciennes 27 - and should provide fireworks.
"We are two teams who play to win," said Saint-Etienne coach Christophe Galtier. "It is going to be an open game."
