The 25-year-old has not featured for the Midlands club since being substituted in the 1-0 win over Fulham on March 10.
The Scot said: "I certainly don't need N'Zogbia's injury. He collided with Gary Gardner in training. Charles was on decent form. I thought he was gaining a bit of momentum.
"He's going to get specialist attention in Paris. We think it's a medial knee ligament problem, maybe three or four weeks."
N'Zogbia, who signed from Wigan Athletic for £9.5m in July, has made 24 Premier League appearances for Villa, scoring two goals.