It might be considered sacrilege, but if you have rings to spare, I would consider trying cutting a new ring, cut the old one off, then with wax paper between the new ring and bumper body, super glue the ends of the new ring together on the side away from where the ball will hit. Taking care of course to also put paper or cloth below the glue area to catch any spills. I have had good luck with both little pin repairs and RC airplanes with the Dollar Tree super glue gel. It takes longer to set, but doesn't run like the liquid.

I generally agree, just thought would offer a way to get it done if he really didn’t want to remove the pops.