Certified GKH Gardening Expert
It is hard to say. If the plant was simply feasted on by a passing slug, the roots may still be ok. If they are strong enough, the plant should regrow its leaves. However, if the leaves were lost due to something else (i.e. disease, nutrient deficiency, etc), the roots may be affected as well and the plant will die. Unfortunately, you may have to simply wait this one out.