The Blues (81 points) currently sit third – four points off table-toppers Doncaster, who can end Paul Cook’s side’s title hopes with a win at home to Exeter.
Despite being the division’s form side, Pompey face a tough task against a Stags team who are chasing the play-offs themselves.
Mansfield (65) are currently just one point and one place outside the top seven and will be hoping for their first home win in three this weekend.
Also hoping to catch Doncaster are second-placed Plymouth (83), who host mid-table Crewe at Home Park.
The Pilgrims drew 0-0 away at Colchester last weekend in their first game since clinching promotion, and they’ll be hoping to return to winning ways this weekend.
Donny themselves have the toughest game of the already-promoted sides – a home clash against fifth-placed Exeter (68).
Darren Ferguson’s outfit seemed to have the title wrapped up a few weeks ago, but three defeats in their past six games have given hope to the chasing pack.
Meanwhile, the Grecians will be hoping to build on a 3-1 win over Morecambe last weekend.
It’s not just the title race that is set to go down to the wire, though, with everyone down to Accrington (62) in 13th still harbouring play-off ambitions.
Leading the charge are fourth-placed Luton (71).
They travel to Stanley knowing a win would guarantee their place in the top seven, while also ending Stanley’s hopes of a late surge to promotion.
Should they slip, though, fifth-placed Exeter and sixth-placed Blackpool (67) will be hoping to pounce.
The Tangerines travel to Notts County on the back of a three-game unbeaten run which has seen them move into the top seven just at the right time.
Gary Bowyer’s side could guarantee their play-off place with a win but they’re relying heavily on other results and it seems more likely to go to the final day of the season.
The final play-off place is currently filled by Stevenage (66).
Boro had been on a brilliant run of form but have stuttered of late and now face a battle to stay in the top seven.
They’ll now be hoping a win against struggling Yeovil will kick-start their promotion bid at this late stage of the campaign and fend off the likes of Wycombe, Carlisle and Colchester in the chasing pack.