Pompey are already short-priced favourites to clinch the League One crown.
And they have the opportunity to tighten their grip on the title race this weekend.
The Blues host 11th-placed Blackpool tomorrow and three points will be demanded from the Fratton faithful.
That’s because Kenny Jackett’s side can take advantage of another crucial promotion game taking place almost 350 miles away.
Pompey’s main two rivals do battle with Sunderland hosting Luton Town.
Jackett’s troops currently sit five points clear of the second-placed Hatters.
The Black Cats a point further behind, although they’ve played one game fewer.
What’s guaranteed from their meeting, though, is at least one club will lose ground on the Blues and it could have ramifications on the race for the Championship.
With that in mind, it’s imperative Jackett’s side pick up a victory over Blackpool.
The Blues have dropped 12 points on their own patch this season.
Draws against Shrewsbury, Burton and Wycombe might be considered missed opportunities by large sections of fans.
Defeat to Gillingham will certainly be regarded that way.
As the business end of the campaign approaches, Pompey can ill afford many more repeats of those results.
Should Jackett’s men deliver a win over the Tangerines – as they did at Bloomfield Road in August – they could potentially open a seven-point gap at the top if Luton and Sunderland play out a draw.
The Hatters’ preparation has been affected by manager Nathan Jones’ departure to Stoke on Wednesday. Mick Halford is temporarily holding the reins.
Jack Ross’ men will see Luton ripe for the taking and victory could potentially put the Blues six-points clear.
If the Hatters deliver a success, Pompey won’t move any further away at the summit.
But promotion is the ultimate aim and it’ll leave Sunderland nine points aback in third spot.
Jackett will undoubtedly be telling his troops to only be focused on Blackpool.
With the chance to put more daylight between themselves and their rivals, though, a victory is crucial.