Rolando Aarons is also ruled out for a month with a hamstring injury while 21-year-old goalkeeper Jak Alnwick will be given his chance to shine after replacing the injured Rob Elliot at half-time against Chelsea.
Premier League rules currently prohibit Pardew bringing in emergency loan cover despite the fact Elliot and regular number one Tim Krul are now likely to be ruled out until the end of January.
And Pardew has urged Alnwick, whose existing contract runs out at the end of the season, to seize his chance.
Alan Pardew: "Robbie will be out for six to eight games so it is a great opportunity for Jak and he is very keen to take it.
"He has had a great start and fitted in very well. He has worked very hard in the background but never had an opportunity. I have great faith in him but he will need a lot of luck as well.
"He is in a great position - if he plays really well in the next seven games it makes it more difficult for us when it comes to contract negotiations. That is definitely in Jak's court."