The 24-year-old is set to undergo an operation on the shoulder injury he suffered in training a fortnight ago.
Interim boss Paul Groves told the club's official website: "It looks like Wes is going to end up having an operation and if that's the case we need to get that under way.
"He adds something different to the rest of the group and has become a very important part of the squad. To lose anyone as important as he is, is a blow.
"It's difficult for any player to be injured and to have to deal with that, but it is part and parcel of the game."