With a bit of luck, you might find that he goes off the cat food and starts looking for alternatives.
I have hedgehogs from the hedgehog hospital in my garden. One of them can't be returned to the wild as she had her nose sliced off by a garden strimmer and she would not survive (as you probably know, hedgehogs rely on their sense of smell to sniff out their food).
She occasionally leaves the cat food untouched. Mind you, I do spoil the hedgehogs with occasional treats of soaked mealworms. (And my hubby is even softer than me - he has, on occasion, hand fed them slugs he has found in our garden).