You can replace just that piece. Your dealer should sell it for around a $100.00. However, if the spa is outside and the cover is 3 years or older, the foam usually will not fit because the vinyl and the foam cores shrink over time due to exposure. I know we can get "short" foam to accomodate this. Short by a 1/2 inch all the way around. But even then, sometimes it doesn't fit in.