After losing to Manchester City on penalties in last season's League Cup final, Liverpool are one step away from a return to Wembley.
Klopp fielded Liverpool's youngest ever line-up against Plymouth in the FA Cup third round on Sunday and the raw rookies failed to impress as the fourth-tier minnows easily held on for a goalless draw at Anfield.
Liverpool can still advance in the FA Cup when they face Plymouth in a replay, but that is on the back burner for now as the Reds focus on their other road to Wembley.
After losing to Manchester City on penalties in last season's League Cup final, Liverpool are one step away from a return to Wembley and Klopp will send out a stronger line-up at St Mary's as he looks to get his side back on track.
Aware of accusations that he and his players were guilty of complacency against Plymouth, the Liverpool manager said: "The question I asked this morning in the dressing room was 'Could we have done better?' 100 per cent yes with this line-up.
"I don't expect perfection but I have high expectations because I see them every day in training and I was convinced we could play really well.
"I have absolutely no problem with criticism but it was not about underestimating an opponent."
Liverpool are hoping to add to their record haul of eight League Cup trophies by winning the competition for the first time since 2012.
That would also be a first piece of major silverware for Klopp, who arrived on Merseyside in October 2015, after Liverpool's defeats in the League Cup and Europa League finals last term.
But before they start to prepare a space in the Anfield trophy cabinet, Liverpool have to beat Southampton and then Manchester United or Hull, who meet in the other semi.
"There is no more pressure on us. It is an opportunity. It is always a new day," said Klopp, who welcomes back Brazil playmaker Philippe Coutinho after an ankle injury.
"I said to the lads last year it would not be the last final they would be involved in and this is the first chance to prove this."
Although Klopp's side have lost and drawn on their last two visits to St Mary's, they thrashed Southampton 6-1 at the same venue in the League Cup quarter-finals last season.
And Liverpool's hopes of advancing to Wembley will be aided by the absence of Southampton defender Jose Fonte.
Southampton manager Claude Puel has confirmed Fonte will not be part of his squad after the club captain handed in a transfer request amid reports of possible bids from Manchester United, Manchester City and Liverpool.
Fonte was absent for Saturday's FA Cup draw against Norwich and Puel has decided to leave him out again.
"Jose won't participate for this game. We will see for the next game. It is important to keep stability," said Puel, whose club haven't reached the League Cup final since a 1979 defeat against Nottingham Forest.
"We do not know the future of Jose, it is a difficult situation in the market. I respect Jose, it is not an easy situation for the staff or players. It is difficult.
"It is an opportunity also for Jose to view different opportunities and it is important to respect this.
"For me, it is important to keep stability in defence first, and second, we will see what the situation of Jose in this market is."