Posh have looked likes serious contenders for an automatic promotion spot all campaign, but their hopes suffered a serious blow when they lost 3-1 to in-form Blackpool on Tuesday night.
That result means they are still second in the table, but Sunderland have a crucial game in hand that would now take them above United, should they win it.
But where do the experts think Peterborough will finish, and who are they tipping for promotion to the Championship?
One set of data analysts have released their latest predictions on how the League One table will finish - and it makes for interesting reading after a busy period in the division, which has seen a number of teams drop points.
Scroll down and click through the pages as we see where their unique formula is predicting Posh to finish come the end of the 2020/21 campaign:
17. 8th - Ipswich Town
Paul Lambert has been sacked after coming under increasing pressure amid fears Ipswich may spend another season in League One - and the experts believe that is likely, even given the appointment of the successful Paul Cook. Predicted points total: 71 Photo: Nathan Stirk
18. 7th - Portsmouth
Kenny Jackett is gone, but can the Cowley brothers lead Portsmouth to promotion? The experts think the side may just miss out on the play-offs. Predicted points total: 73 Photo: Mike Hewitt
19. 6th - Doncaster Rovers
The departure of Darren Moore (above) could harm Donny's hopes of automatic promotion, but the experts believe the play-offs remain a realistic aim. Predicted points total: 75 Photo: George Wood
20. 5th - Lincoln City
The surprise package of the season, many have tipped Lincoln to fall away in the second half of the season - but the experts don't think that will be the case. Predicted points total: 76 Photo: Mike Hewitt