Yellow patch on my Sarcophyton

Hi again folks! Its been a while!

I had a period where i lost my entire tank due to vandals trashing my house a year ago and tripped the power whilst i was on holiday!

So i went nano for a while but have just stripped the two nanos down into a 240ltr as they were doing too well!

Anyway i now have a Sarcophyton in one of the nanos i am using as a quarantine tank - i have had it for three days and it is lovely with almost full polyp extension except for a small 1cm patch on the rim that is yellow where the rest of the coral is tan brown with yellow undertones.

the polyps on this patch are only half extended and whiter than the rest of the coral!

Any sugestions as to what this can be and how to remedy it? is this necrosis or just a slightly damaged portion caused due to handling?

Should i just observe it over time or is it best to be proactive and cut the area out?

Any suggestions will be greatly appreciated and it is great to be back in full swing again!

 

a picture would help

 

a pic will def help us give you a better idea on what is happening. but from my experiences with my green polyp sarcophyton (the toadstool corals right?) mine seemed to really react negatively when its too close to the lights., also could be shedding and that section still has a piece of flesh mucus whatever stuck to it. they seem to shed more often than my other leathers. this could be just its situation in my tank, but its in a damn good spot and still likes to shed. so there is two things to start, but a pic will help more.

 

Will try and get a photo up tomorrow thank you.