Sheehan is one of 15 players out of contract this summer, but the 26-year-old left-back has held initial discussions with Magpies manager Chris Kiwomya about a new deal.
He told BBC Radio Nottingham: "I have had two years here, have played over 80 games and I am happy to be here.
"The fans have been very good. I'd like to be here and have never said I want to leave.
"A few of us have spoken to Chris and we know his plans for next season. I can't really say too much before things goes public but he has plans for next season.
"I think it will be quite exciting and it will nice to be a part of it."