The France international will have an operation on his damaged groin either later this week or at the beginning of next week after limping out of the 1-0 Premier League defeat by West Ham two weekends ago.
Pardew said: "He 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."
Cabaye will definitely miss the Europa League clash with Maritimo at St James' Park, and Pardew also has a doubt over striker Shola Ameobi.
He said: "The only one we are a little bit concerned about is Shola this morning. He's got a slight groin niggle, so we are going to have to see how he shapes up for tomorrow's game."
Meanwhile, Pardew has insisted owner Mike Ashley is well aware of the strains European football is placing on his injury-hit squad.
The Magpies will reach the knockout stages of the Europa League if they can beat Portuguese outfit Maritimo at St James' Park on Thursday night, and that will ensure their first foray into European competition for five years will extend into the new year.
However, while Pardew's men are unbeaten in Group D and have defeated both Bordeaux and Club Brugge on Tyneside, they have been unable to repeat the domestic form which secured a return to continental action last season amid a rash of injuries and suspensions which has exposed the relative lack of depth in the squad.
Ajax midfielder Vurnon Anita was the only senior player added to the squad during the summer as Ashley and managing director Derek Llambias stuck to their valuations, although the manager revealed they are well-versed on the matter.
Pardew said: "We are all concerned. It's not like it's just heaped on myself and 'Get on with it'.
"The managing director and the owner are very conscious of where we are and we are trying to make sure that we look at the period and events leading up to the next window, and we will react from there."
- Sports & Recreation