Marine Betta - check out the picture?

[Stew18]

I have a 2.5 inch marine better that is currently in QT and has been for a month. I had ich in my tank and have moved my 3 fish to QT. The other days I noticed this brown circle on his side and part of his top fin was missing. It looks as though he scraped something?

I suppose he could have been bitten but the only other 2 fish I have is a tiny Yellow Assessor Basslett and a 1.5 in starry blenny.

Also, the betta has been acting totally normal and eating fine

I have a rock in QT that fell over the other day so maybe it fell on him?????

Thanks for all your help