Ahh
That I am afraid sounds pretty terminal, if you do pull it up, have a look at the rhizome and give it a gentle squeeze, if it is firm and still has healthy roots on it, it may yet be resurrected, but if it is a brown mush its a gonner. Of there is somne firm and some rotten rhizome, cut away the rotton part to a healthy part (white coloured inside) put some fungicide on it and replant, although disturbing it at this time of year is not recommended.
Best of luck - but I fear the worst.
Cheers
Steve