Karl Robinson makes six changes to the side that drew 0-0 with Shrewsbury Town on the weekend, bringing in five players under the age of 22.
Ian McLoughlin, Tom Flanagan, Ben Reeves, George Baldock and Patrick Bamford are all included in Robinson’s starting XI along with defender Jon Otsemobor.
McLoughlin will start in goal behind a back four which consists of Lee Hodson at right-back, Shaun Williams at left-back and Flanagan and Otsemobor in the centre.
In front of them, Reeves will partner Stephen Gleeson in midfield while Baldock, Dele Alli and Jason Banton will make up an attacking trio which will support Bamford up-front.
The Dons, whose starting XI has an average age of 21, do have plenty of experience on the bench if needed, with David Martin, Luke Chadwick, Alan Smith, Izale McLeod and Antony Kay all amongst the replacements along with youngster Brendan Galloway.
Northampton Town: Duke, Amankwaah, Widdowson, Heath, Collins, Tozer, Deegan, Emerton, Morris (c), O'Donovan, Hooper.
Subs: Snedker, Moyo, Dias, Artell, Demontagnac, Toney.
MK Dons (4-2-3-1): McLoughlin; Hodson, Flanagan, Otsemobor, Williams; Gleeson (c), Reeves; Baldock, Alli, Banton; Bamford.
Martin (GK), Chadwick, Smith, McLeod, Galloway, Kay.Subs: