Darren Ferguson's side can go level on points with the league leaders with victory at home on Saturday, although second-placed Wolves will be hoping for a slip up from either team
Russell Slade's side top the division after winning 11 of their first 14 fixtures, a run in which they have lost just once and scored a league-high 33 goals.
Peterborough, who sit third, have stuttered in recent weeks, following a goalless home draw against struggling Sheffield United with a 1-0 defeat at Colchester United.
Sandwiched between the two sides are Wolverhampton Wanderers, with Kenny Jackett's side boasting the meanest defence in the division.
Wolves – who have conceded just eight goals in 13 league matches – host 17th-placed Stevenage on Saturday.
The visitors have found form after a poor start, winning three of their past four matches.
Hoping to make up ground on the leading trio are Preston North End, and Simon Grayson's side will be hopeful of closing the six-point gap to both Peterborough and Wolves when they take on struggling Tranmere Rovers at Deepdale.
Tucked in behind Preston in the remaining two play-off berths are Brentford and Bradford City, who both face away trips on Saturday.
Brentford, currently enjoying a three-match winning streak, travel to 12th-placed Crawley Town while Bradford, who have claimed just one point from their past four games, take on third from bottom Crewe Alexandra, who have lost their last two.
Hoping to climb into the top six will be Walsall, who travel to Milton Keynes Dons having won just two of their past seven games, while their hosts are similarly out of form, tasting defeat in four of their last five matches.
Two more teams just outside the play-off spots are Swindon Town and Port Vale, who will face each other at the County Ground.
Port Vale have won their last two, while Swindon have lost two in a row.
Rotherham United are level with Swindon and Port Vale on 20 points and Steve Evans' side will be looking for their first victory in five matches when they host 14th-placed Colchester United.
At the bottom of the table, Bristol City, who tasted success for the first time this season with last weekend's 4-2 triumph at Carlisle United, host 16th-placed Oldham Athletic while second from bottom Notts County face a tough trip to Coventry City, who are unbeaten in five.
Other fixtures will see Shrewsbury Town host Sheffield United, while Gillingham take on Carlisle United.