The twenty-three year old has had a successful loan spell at the club this season with 20 appearances in the Newcastle first team, before returning to Manchester on Tuesday.
Reports claim personal terms have been agreed by both club and player and once Simpson completes a medical he is expected to sign a two-and-a-half year deal.
The youngster had seen off competition from Ryan Taylor to make the right-back position his own this season and has been a vital part of the tightest defence in the Championship.
Elsewhere Nottingham Forest are reported to have knocked back a bid for midfielder James Perch. Assistant Manager Colin Calderwood obviously knows the player from his time with Forest but it is unlikely the Reds will sell on the cheap to one of their main promotion rivals.
Forest boss Billy Davies dismissed the offer out of hand, saying, "We are looking to build a squad at the City Ground rather than dismantle one and James is not leaving.
"Newcastle's offer for someone we value so highly as a player and an individual was derisory and I'm disappointed it made it into the public domain."
And finally, Toon target Jermaine Beckford is now being linked with a move to Everton. Personally this is a non-starter for me, Moyes is an astute man and I'm sure he can find a much more suitable striker to fire Everton back towards Europe than Beckford.
In fact the more I think about Beckford's decision to withdraw his transfer request the more I think perhaps we knocked him back. Lovenkrands is scoring, Shola is fit and Carroll is always a threat at this level.
With goals coming from the middle of the park too, do we really need another striker?
Perhaps one more on loan just to sure things up. Harewood did a decent job but if he was coming back I would've expected it to have happened by now. My choice would be to make a cheeky offer for James Beattie, who is apparently not on the best terms with Tony Pulis at Stoke.
A loan until the end of the season would bring in a proven goalscorer and, in my opinion, a quality player. Just the boost we need to kick on to the end of the season.