Simpson has established himself at right-back in a defence that has kept 13 clean sheets, but Hughton is weighing up all his transfer window options and has yet to strike a deal.
Simpson said: "At the moment, my last game is January 9 against Reading. I think there have been bits and pieces of talks between the two clubs, but there's nothing concrete.
"Everyone keeps saying that Man United are short of defenders at the moment, but a few are coming back soon and I've only got six months left on my contract there, so whether it would be right thing to stay there or not, I don't know.
"But I'm happy here and if something can be sorted out, I'd like to stay. I haven't heard anything at all from Man United. My agent will start speaking to them soon and we'll find out what the situation is and take it from there with Newcastle .
"You don't want to be left in limbo. I'd like it to be sorted before the loan deal ends, but things like that don't happen straight away and it could take up until the end of January. I could go back to United and then come back here a couple of weeks later, I don't know, but I'd love to be sorted out earlier as a nice Christmas and birthday present."