A sold out Fratton Park hosts its biggest match of the season as fellow promotion contenders Luton Town visit looking to leapfrog Portsmouth in the table.
Gary Roberts is likely to return to the starting eleven after being rested for the previous two matches whilst Jamal Lowe has officially left Hampton & Richmond and may be included in the squad.
Nathan Doyle and Danny Green are missing from the Hatters' squad tomorrow with Achilles and leg injuries respectively.
Fourth-placed Pompey face the first of their two season-defining fixtures tomorrow with the visit of fifth-placed Luton to Fratton Park and the managers of both teams will know that a draw does neither of them any good with the top three already seven (or eight in Luton's case) points clear of the play-off positions. It wouldn't be too dramatic to claim that the loser of this game can kiss their chances of automatic promotion goodbye.
Therefore, it would be safe to assume that tomorrow's match will be an open one, especially as Cook is likely to either play the 4-4-2 formation he used against Newport or the 4-3-3 setup that was deployed in the fog at Yeovil.
Having said that, the 4-2-3-1 formation did yield Pompey's best performance of the season in the reverse fixture but as much as the manager might be tempted to revert back to his favoured formation, the safe bet is that he will stick with the 4-3-3 used at Huish Park and replace either Noel Hunt or Michael Smith with Gary Roberts as he would be foolish to drop Kal Naismith after his performances in December.
In terms of other attacking options, it'll be interesting to see if Jamal Lowe makes the bench tomorrow and if Conor Chaplin starts having not started a match for a while now.
Luton's form has been patchy since the two teams last met with two wins, two draws and a defeat in the league. There have been hints that Nathan Jones may set his side up to frustrate Pompey and take a draw but he doesn't really have the players to do that and, as mentioned before, a point won't do his team any favours due to the gap between themselves and Plymouth, Doncaster and Carlisle.
Argyle travel to Barnet in a fixture they may drop points in but the Cumbrians and Rovers host Grimsby and Stevenage respectively thus it would be optimistic to expect them to slip up. Therefore it's almost imperative that Pompey pick up the three points tomorrow.
They certainly can't afford to lose ahead of the second key match in the promotion race at Doncaster on Thursday.
Predicted Starting Line-Ups
GK: David FORDE
RB: Gareth EVANS
CB: Christian BURGESS
CB: Matt CLARKE
LB: Enda STEVENS
CM: Michael DOYLE
CM: Danny ROSE
CM: Carl BAKER
RWF: Gary ROBERTS
LWF: Kal NAISMITH
CF: Michael SMITH
GK: Christian WALTON
RB: James JUSTIN
CB: Johnny MULLINS
CB: Glen REA
LB: Alan SHEEHAN
RM: Olly LEE
CM: Cameron McGEEHAN
CM: Pelly Ruddock MPANZU
LM: Alex GILLIEAD
CF: Danny HYLTON
CF: Isaac VASSELL
Last Time: Portsmouth 0 Luton Town 0 (League Two - 28/12/2015)
Andy Awford returned to Fratton Park for the first time since being sacked as Pompey manager and he managed to get one over his successor as the home side were held to a drab draw.
Pompey's home form has been poor but for some reason I believe a formation change and Luton's approach to the match will see 2017 begin with a much needed victory.
Portsmouth 2 Luton Town 1