The French midfielder requires an operation on a groin injury sustained in the recent defeat to West Ham and will be absent for a number of weeks as he recovers
The 26-year-old limped off at the end of the clash with the Hammers, and subsequently missed his side's 2-1 home defeat to Swansea on Saturday.
And Pardew is rueing the loss of the France international as his side bid to overcome their sluggish start to the Premier League season.
"[Cabaye] will definitely have an operation, and we think it's going to be on Friday or Monday, I'm not sure. That's a blow to us because he's a top player for us," he told reporters.
Pardew also expressed concern over Shola Ameobi's fitness ahead of Thursday's Europa League clash with Maritimo.
He added: "The only one we are a little bit concerned about is Shola. He's got a slight groin niggle, so we are going to have to see how he shapes up for Thursday's game."