keep your water quality high and offer foods when the tenticals are out fully but inly small stuff like mysis shrimp. and hope for the best. watch for signs of it getting worse though anemones can die quickly and pollute the tank and that is a bad thing. normally if the disk is torn its only a matter of time though. I have most will be fins as long as that isnt damaged in and is secluded to jsut the tenticals, in this case its both so keep an eye on it and keep your fingers crossed.
Mike