They may not, but a herniated disk tends to spill out, like really a disc-shaped elastic container
(annulus fibrosis) of thick molasses (nucleus pulposus), and while it may stabilize and heal to a significant degree, the tear in it can (more) easily reinjure, since it does not have the integrity of the uninjured disc (which is why Eichel's surgeons threw in the towel and gave him a synthetic one). In a contact sport, that gradual degradation of the disc has a higher probability of happening again than it would in a pristine disc, so that the hole in the elastic container can reopen again, spilling thick molasses onto that sciatic nerve.
Lumbar Disc HerniationView attachment 887499