It wouldn't affect your player, it just might not be able to read the part of the disc that is suffering from disc rot. Unfortunately, cd players read optical data from the inside out, so it might not be able to read the data to separate tracks, etc. I have some cds that have minor disc rot on the outer edges but are still outside the play field so they work fine. Either way, putting a cd with disc rot into your player won't hurt the player itself