I wouldn't sweat it.

My advice would be to wait a week and then feed the same prey he had been eating. This will most likely get him eating regularly for you without much of a problem. Many prefer rats to mice, so if you can find rat pups I would try to stick to that. This way, as he grows you can just up the size of rat to be the right size for him. Since he's on rats, trying mice might be tricky, and then back to rats when he outgrows mice.

If you can't find rat pups at a local shop (I can't find any in my area, so I'm picking some up at a reptile expo near me n a few weeks. Cheaper than online) then I would say you'll be fine with mice if he takes them.

Keep us posted, good luck!