Citing Faculty in Writing Sample

[Eliza123]

I wrote the writing sample that I sent along with my application a while ago. Since then, a professor at a school where I am applying has written a short text about the same subject (published in 2016). Is it necessary for me to go back and edit my sample and add his text to my bibliography? Or can I just leave the text as is. Will this professor understand that, if his name is not in my bibliography, I wrote it before his text came out? Thanks! 

[fuzzylogician]

If you've already submitted the application, let it go. If you're still working on it, I would edit the text to add the relevant citation, if it's not too much work. There is no way for the professor to know when you wrote your text, so it'd be good to avoid anything that he could interpret as you missing a relevant citation.