Brad Drew did something similar last year and it put him out for half a season. That said I have no idea if Sherwins injury is the same but they can be troublesome.
Agree with Mattsbury, should be ok strapped up, if he was OK to carry on playing on Saturday, can't see it being too much of a problem, tough little cookie is Shifty!
I can't believe after last season (I know he had injury problems) how big of a player Brent has become for us. He is the general who directs us round the field and orchestrates everything we do. Those long passes he does remind me alot of Paul Cooke when he was at Hull FC.
Hopefully he will be able to play and to the best of his ability on Friday.