Yeah it just looks like he cut/scraped himself on something. I don't think it's from a cricket; they tend to bite extremities, not faces. Besides a healthy animal, even a sleeping one, will feel a cricket and shake it off. In my experience it's the debilitated animals that get picked on by bugs.
I thought that PolySporin was found in the UK which is why I suggested that one. I think the Savlon antiseptic cream (
http://mccabespharmacy.com/shop/health/first-aid/first-aid-accessories/savlon-cream-15g.html ) would be equivalent to our PolySporin but what you've got would probably be fine too. You basically want to keep that area clean until it heals up. Remove any bugs at night
just in case and maybe double check to see if there are any sharp objects in his cage or outside time area.