clownfish has weird mark on side

I know this is almost a lost cause asking without a picture but my clown I have in quarintine has a fairly large almost grayish blotch on his side it isn't a lot of discoloration but it was enough for me to notice something was different. I isn't ich it almost looks like a big scrape but I am not sure. I tried to get a picture but I can't get one that actually shows the mark at all so there was no point in uploading it.



The blotch almost goes from stripe to stripe and is a fair portion of the upper half of him. Any ideas on what it could be or am I just being paranoid. Glad I deciced after much research when starting this hobby to quarintine since I have never had a problem until now it will pay off if he is sick.