West Ham United's win over Sunderland has placed the Londoners above Roberto Martinez's outfit and Burnley's surprise success at Hull City has narrowed the gap between them and a place in the bottom three to just four points.
With five games to go, Wigan must see off the challenge of Pompey but, on the back of their excellent FA Cup semi-final 2-0 extra-time win over Tottenham Hotspur on Sunday, they will be in confident mood to get a result in the north west.
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Avram Grant's side, on the power of the Hammers' three points on Saturday, will now ply their trade in the Championship next term and many of their players may well want to impress in order to grab new contracts or put themselves in the shop window.
There is no reason why the south coast club can't go and collect the three points with Wigan in such poor form.
A 1-0 success over Burnley in between losses to Bolton Wanderers, Aston Villa, Manchester City and Fulham does not make for easy reading in the north west.
Although Pompey have collected just one point from a possible nine recently in the league, their hard-fought FA Cup success may bring a new found belief despite enduring a terrible season in the main.
Back-up goalkeeper Richard Kingson is out with a groin problem while Emmerson Boyce faces a fitness test on his troublesome back ahead of the clash.
The visitors could welcome back Nadir Belhadj (thigh) and Tal Ben Haim (groin), but long-term victims Danny Webber (cruciate ligament) and Hermann Hreidarsson (Achilles) are definitely out.
Last season's fixture between the sides ended with the hosts grabbing the glory on the final day of the season.