Portsmouth must dig deep if they are to boost their London two south west survival bid against Effingham & Leatherhead at Rugby Camp (3pm).
The Norway Road club occupy the second relegation spot going into their final four games but have a game in hand on Trojans, who are five points above them.
A bonus-point success over the Surrey visitors will draw Portsmouth level and leave them just three points adrift of their visitors.
The relegation dogfight is going to the wire and Nigel Morgan knows the final few weeks will be all about discipline and temperament.
‘If we can win three of our last four games we believe we will stay up,’ said Portsmouth’s first-team manager.
‘This is not a must-win game but our situation will become more difficult for us if we don’t win it.
‘We can’t really afford to slip up and this game will be every bit as tough – if not tougher – than the one against the league leaders last week.
‘Mentally and physically, this will be more demanding.
‘Although we ended up losing against Guildford, the players can take a lot of encouragement from their performance.
‘They played with an increased intensity and it is vital we maintain that in this game.
‘We were able to play without any great pressure on us because we were not expected to get anything from that game.
‘This will be different and how we handle it will be all-important.’
The home side are bringing winger Matt Gronow back in from the veterans’ side, believing his experience and quality could make a difference.
The 40-year-old has regularly proved he is still one of the quickest and deadliest finishers at this level.
With the pacy Curtis Barnes on the other wing, Portsmouth are hoping their fire-power will help blow Effingham away.
It will all hinge on whether the Portsmouth forwards can provide the three-quarters with the necessary ammunition, though.
‘Undoubtedly, the game is going to be won or lost up front,’ said Morgan.
‘If our pack of forwards can reproduce the form shown in our last game then they will give us a good chance.
‘With possession of the ball we believe we have the fire-power outside to get the result we need.
‘Earlier in the season we would have beaten Effingham if we hadn’t dropped the ball over their line in the final seconds.
‘They have improved since then and their good win over Old Reigatians last weekend suggests they are a better team than their position suggests.
‘We cannot afford to be anything but at our best.’
With Dan Stoneman unavailable, Alex Lamont is drafted in at number eight.
And the home side are waiting on the fitness of centre Gareth Richards.
Richards missed the last game through illness and his presence will depend on how he trains before the game.
Portsmouth (from): Barnes, Norman, Gronow, Gates, Richards, Harris, Chandler, C Morgan, Cuming, Hoolihan, Nicholls, French, Reddin, Giquel, Lamont, Long, Phillips, Crook, Fooks, Hazeldine, Owen