The Italian was issued a second booking for a shirt pull less than a minute after half-time , but his coach insists he is not angry with the 21-year-old playmaker
The Italian was booked in the first half for a deliberate handball before he was shown a second yellow card for a shirt pull less than 60 seconds after the interval.
PSG went on to seal a 2-1 win thanks to Edinson Cavani's last-gasp goal and Blanc maintains he will not come down hard on Verratti for his two indiscretions.
"The first booking, he deserved, but it wasn't a dangerous play. It's stupid, but it stops the attack. Sometimes it helps the team," Blanc was quoted as saying by RMC.
"Verratti made two mistakes in this game. I'm not trying to defend him, but let's say it wasn't indefensible. I don't want to blame him, even though it put us in trouble."
Thiago Motta admitted the red card made life "complicated" for the French champions but was proud of the way his side fought for the victory.
"We were cleary superior in the first half. It complicated life for us, but the result was victory and qualification. We won with out heart. It was important for the team to win in these conditions," the Italy international told Canal Plus.
Defender Maxwell compared the result to a 2-1 win over Olympique de Marseille in October, when PSG again battled to victory with a man down.
"It was the same again," the Brazilian added. "We lost an important player but we continued to play.
"We're very happy; we qualified, which is the important thing. We showed great strength, confidence, heart and desire."
The result guarantees les Parisiens a place in the last 16 of the Champions League as winners of Group C.