The 31-year-old goalkeeper suffered cartilage damage after twisting his knee in training last Tuesday and went under the knife on Friday morning.
He missed Saturday's first away win of the season against Aldershot and although veteran Andy Warrington came in and kept a clean sheet in a 3-0 victory, boss Steve Evans will look to bring in another keeper.
"Scott twisted his knee in training last week," Evans said. "As a result he has had minor surgery but he will not be fully fit for selection for perhaps five or six weeks.
"Andy Warrington is a top goalkeeper and is desperate for his chance. I will now look at the situation with a view to bringing in a goalkeeper to compete with him and we will now get on with that in the next few days."
- Andy Warrington