Kenny Jackett's side moved four points clear at the top of the table when they beat Colchester United 4-2 and second-placed Brentford were beaten 3-0 at Rotherham United on Tuesday.
The Midlands club have a seven-point advantage over third-placed Leyton Orient with a game in hand, but Jackett is taking nothing for granted ahead of the clash with Karl Robinson's play-off hopefuls.
He told the club's official website: "We know the issue of trying to win promotion is there,
"When we came back on June 24th our aim and ambition was to get promoted and so we have talked about it all year.
"But it is not something we should be focusing on now because we should be focusing purely on MK Dons.
"We know it is there in the background but breaking it down into different bits helps you try and get towards a long-term goal."
Brentford had won four games in a row before they were brought back down to earth by Rotherham and will be eager to get back on track at Oldham Athletic.
The London club had conceded only one goal in their five matches before the midweek setback and they face an Oldham side coming into the game on the back of a 1-1 draw at third-placed Leyton Orient.
Orient have lost their way after spending so long at the top of the table and go in search of their first win in four matches when they host Bradford City.
Fifth-placed Rotherham will be looking to stretch their unbeaten run to 15 matches when they host Bristol City, while Preston North End - level on points with Steve Evans' side - entertain Crawley Town.
Peterborough United - who occupy sixth spot in the table - face Chesterfield in the Football League Trophy final on Sunday, so there is an opportunity for the sides below them to make up some ground on Saturday.
Swindon Town and Sheffield United both harbour play-off hopes and they meet at the County Ground, while ninth-placed Walsall host Shrewsbury Town.
Just six points separate the bottom eight sides in the table and bottom club Stevenage will be striving to secure their first win in five when they host Port Vale, while Notts County will be just three points behind Colchester United if they beat them at Meadow Lane.
Crewe Alexandra host Coventry City, while Tranmere Rovers face Carlisle United at Prenton Park in the other game to be played on Saturday.
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