The defender is also wanted by Fulham and West Bromwich Albion, but that has been the case for months, and neither club has made any offer.
West Ham were also mentioned, but they too, have kept their distance.
Simpson is sidelined with a foot injury, so any deal could be a risk, and the 26-year-old is understood to be open to a loan move.
Simpson would then be able to leave St James’s Park on a free transfer at the end of the season.
Simpson has been the club’s first-choice right-back since joining from Manchester United in 2009, initially on loan, and it surprised my fans when the club allowed him to go on the transfer list.
But talks over a new contract broke down last season, as he told fans he was on £10,000 a week - a quarter of what Mike Williamson is on..