I've noticed that the rubber surface on the left finger holder

I purchased a used mouse, which has been functioning perfectly. However, I've noticed that the rubber surface on the left finger holder has started to peel off, exposing the glue beneath. While I can temporarily push the surface back into place, it eventually comes off again. This is a cause for concern. I'm considering using super glue to fix it, but I'm not sure if I should first remove the existing glue and then apply the new glue to the surface. What would be the best course of action?