As things stand, Pompey are sitting in sixth place with 65 points, but, in a tightly-packed division, a poor run of results in their final handful of matches could see them surrender their spot to one of the chasing pack over the course of the final six games.
But what are the data experts saying about how the League One table will finish?
We've take a look at the third-tier and every club's predicted position and points totals, according to data experts FiveThirtyEight. This is where Portsmouth and all their divisional rivals are tipped to finish:
17. 8th - Oxford United
Predicted League One position: 8th. Predicted League One points total: 71 Photo: Richard Heathcote
18. 7th - Charlton Athletic
Charlton Athletic will fail to secure a play-off spot according to the data experts, and are projected to finish on 75 points. Photo: Stu Forster
19. 6th - Portsmouth
Pompey will secure sixth position and grab the last play-off spot, with 75 projected points. Photo: Naomi Baker
20. 5th - Lincoln City
Lincoln City will finish fifth according to the data experts with a projected points total of 76, meaning they would make it to the play-offs. Photo: Joe Portlock