The former Cefn Druids goalkeeper joined The Saints during the summer and has now signed with Newtown until the New Year.
Mullock famously kept a clean sheet against Finnish outfit MyPa in the Europa League first qualifying round and the TNS number 25 has agreed to join Bernie McNally’s Robins.
‘Mulls’ will go straight into the Newtown squad for Saturday’s Corbett Sports Welsh Premier League game against Bala Town.
Speaking about the move, Craig Harrison said, ‘Chris has done fantastic since coming in at the start of the season. His attitude as well as his work ethic has been a joy to coach and now that he has adjusted to full time training, he needs to go out and play games at this level.’
The former Middlesbrough man went on to say that, ‘He is more than capable of playing in the Welsh Premier League. There is nothing worse as a player if you train everyday and then there is no match at the end of the week. Chris will go and get games at Newtown up until January and we will go from there.’