However Gray is keen not to rush the key player back and after the Cobblers scored four goals last week in the remarkable draw at Scunthorpe may leave him on the bench.
Midfielder Luke Guttridge is fit again after missing that draw with a neck injury but could also struggle to force his way into the starting XI.
Captain Chris Doig remains out with his hamstring injury so on-loan Derby defender Andy Todd will make up a back three with Mark Hughes and Jason Crowe.
Chris Dunn is set to keep his place in goal despite conceding four times at Glanford Park so Manchester United youngster Ron-Robert Zieler will stay on the bench.
Carlisle manager Greg Abbott is set to have defender Peter Murphy available.
The centre-back showed no reaction to the thigh problem which kept him out of the 2-1 defeat to Leicester as he completed 45 minutes in the reserves' 6-1 thrashing at the hands of Newcastle during the week.
Skipper Paul Thirlwell will visit a specialist in a bid to clear up on-going calf injury and is set to miss out but striker Danny Graham has recovered from an arm injury.
Experienced midfielder Graham Kavanagh will continue after he extended his loan deal until January 3 while Simon Hackney, Chris Birchall, Grant Smith, Gary Madine and Scott Dobie are all pressing their claims to be involved.
Sporting Life