Saints meet Spurs for the 4th time this season and according to Ralph Hasenhuttl they go to North London without fear, but what team will he put out.
Ralph Hasenhuttl knows that after this game his team have a 10 day break before their next game and this may swing his team selection thoughts knowing that with a home draw against Norwich City awaiting the winners the competition could open out if Spurs can be overcome.
Spurs too have a similar break, but Jose Mourinho has injury problems of his own and when he returns to action his team have three important games in the space of six days including a home tie in the Champions League against RB Leipzig, ironically Ralph Hasenhuttl's former club before joining Saints.
Ralph has said we will play without fear and that has been a feature of our displays of late and hopefully the late goals against Liverpool will not have dented our confidence.
I think we will play our strongest side, but the big question will be who plays right back.
At Liverpool he played JWP who had a decent enough game but you feel it took something out of the midfield, so will he try another option there and restore Ward Prowse to his rightful position.
It won't be loan signing Kyle Walker Peters, he was not signed before the original game so cannot play in the replay, likewise Steven Bergwijn for the home side, he scored on his debut on Sunday to help beat Manchester City, but for the same reason as KWP isn't available.
So will Ralph opt for JWP again or put in Kevin Danso who has played in all the FA Cup games so far, given the club blocked the players move back to Germany, Danso will be pretty hacked off if he doesn't get a chance.
Spurs have turned their form around since the arrival of the Special One, at home they have won 7 out of 9 games, but their overall form is a little patchy and most of the hme games have been against those sides who struggle on the road, Burnley, Brighton and Bournemouth being three, so the record is not as impressive as it looks at first glance on paper.
However it cannot be denied that they are still a formidable team, but without Harry Kane they struggle to score goals and don't have his replacement available as said earlier.
Saints have played well against Spurs though and they go into this game honours even, losing at Spurs in the League and beating them at home, with the 1-1 draw in the original tie meaning that winner takes all tonight.
I expect our best side out and I think Ralph will oblige with the only real question being who plays at right back and who will be up front alongside Danny Ings.
The game is there for the taking, as Ralph says we have nothing to fear, get a win in this one and we can see a clear path to Wembley ahead of us, why would we not want to take it !