Krul missed Holland's game with Iceland yesterday after being injured in training and he underwent a scan yesterday to determine the severity of the problem.
The Magpies No 1 has suffered a similar problem in the past and was out of action for six weeks.
Rob Elliot, on international duty with Ireland, is in line to face Leicester.
Pardew is also without Krul's Dutch team-mate Siem De Jong until January, although the £7.5m buy from Ajax is not certain when he will be back to full fitness from a thigh injury.
De Jong: “It’s hard to say when I will be fit again. It is going well and I feel good but it is a nasty injury. I hate it even more as you want to help the team but you can’t.”
The 25-year-old has only made three appearances this season.