This is a biggie not just for Saints but for Norwich City as well, if Saints can win then they could move out of the bottom four and bring the rest of the pack in front into the relegation dogfight.
Watford was a very important game, by beating them we gave the supporters hope again and now we have to consolidate those three points by gaining another set in quick succession.
This means another gutsy performance where we never give up either on or off the field, on Saturday for a long period it did not look good with plenty of possession but little imagination and real chances to the final 15 minutes and it is going to be the same again tonight.
Our expectations need to be realistic, we know what the issues are they cannot be changed overnight, we are not going to suddenly become a great all round team who can defend like Trojans and tear sides apart, but we can be a side that gets points through sheer determination, if we can keep the opposition out then we have plenty of match winners in the side.
So this game will not be for the purists, it will see defensive mistakes, but we have to hope that like Saturday we don't get punished much or even at all.
Against Watford the best thing was the spirit showed by the players in keeping going even when things weren't going well and for some the harder they tried the less it came off.
Tonight I don't think Ralph will deviate much from the starting line up from the weekend, but I think he will make a change or two.
At the back there is a case for Yan Valery to be restored at right back in some fans minds but I have to say that I didn't think Cedric had as bad a game as some would have you believe, the major chances that the Hornets had were not down to him and I would say that Ryan Bertrand struggled more than Cedric in marking.
The only other change for the manager to consider is Michael Obafemi, the youngster has pace, that cannot be denied, but he is yet to show either the skill or finishing of Djenepo and he is at a crossroads in his career at present.
This will be perhaps the one change in the side if any, but who would Ralph replace him with, perhaps the time to throw in Che Adams could be tonight, the summer signing from Birmingham has talent, but earlier in the season couldn't buy a goal, perhaps after a rest that could change.
Sofiane Boufal would have been an obvious swap for Obafemi, but he has his toe problem, personally I think he is more effective coming off the bench for a late power play as happened on Saturday and I would expect that again tonight.
Other than these potential changes I think the team will be pretty much the same, I was surprised to see Nathan Redmond, James Ward Prowse & Pierre Emile Hojbjerg get so much stick after the game, yes Redmond did not have a great game, everything he tried failed to come off, but good players have off games and this was one of his, but he is potentially our best player as he proved last season and earlier in this, form is temporary class is permananent.
Hojbjerg plays a role that earns little plaudits, he is the carryer, get the ball carry it and then move it on, hs job isn't to create but get the ball to those who can, he will perhaps only be appreciated by some when he is gone.
Finally James Ward Prowse, for some he will never be any good, yet this season he has been a consistent performer despite being played in several different positions, out of our 15 League goals he has scored 4 of them, he is the one player in the team who can pick a pass and open up sides, yet he is often the most maligned.
So tonight is going to be once again about getting behind the team and every player in it and for the full 90 minutes, they showed on Saturday they will not lose spirit, not lose hope and not give up till the final whistle and that has to be the same for the supporters, as long as their is still a chance of a win or a point then we all should be there to see it and if necessary will the ball into the net if nothing else.
As older supporters know from the 1990's if we are to survive then we need a siege mentality, at the moment we have backed ourselves into a corner with fans leaving the game at half time on Saturday or midway in the second half, we have talked ourselves into a losing mentality, created a negative vibe in the stands and this has to stop.
Saturday was the lowest crowd at St Mary's for a Premier League match for a long time, from memory there has only been one lower and that was back in 2001 for a Monday televised game in our first season.
But this was as good an atmosphere as any other game this season, football crowds are not always about numbers to create an atmosphere, sometimes when a crowd is low as on Saturday it means you have lost some of the negative elements in that crowd and I think that was the case against Watford, in the final quarter we had the hard core left willing to get behind the team and that helped.
I hate the Premier League and what it stands for, but I want my club to play at the highest level and that is this division, people talk about the good old days back in League 1, they were good fun but they weren't that good, ask the 16,402 who turned up to see Wycombe play at St mary's on a cold evening 10 years ago this very week, nostalgia ain't what it used to be.
But now is now, football clubs go through good and bad times as was shown back then, when the team plays get behind them, this is not happy clapping it is called support.