The Elland Road club head to Leicester City looking to claim a second top-flight scalp of the season after dumping Burnley out of the Carabao Cup in the previous round.
Leicester sacked Craig Shakespeare last week following a poor start, but a 2-1 win at Swansea City over the weekend helped move the Foxes out of the relegation zone and up to 14th in the table.
Christiansen’s side are also fresh from a victory on the road after shattering Bristol City’s unbeaten home record thanks to a double from Samuel Saiz and a Pierre-Michel Lasogga strike.
“They had a good win this weekend,” said the Dane about the side who sit between Leeds and a place in the quarter-finals for a second consecutive season.
“It was a win that can also give them their confidence back. You never know when is a good time (to play Leicester).
“When a team is hurt and they are suffering down in the table, that is probably when it is most dangerous to face them. They had a win last week without a new manager so anything can happen.
“But we faced Burnley (in the third round) when they were seventh in the league, playing well and getting important points yet we managed to qualify for the next round. For me, this is a beautiful game against a Premier League team and there will be a good atmosphere.”
United’s clash with Sean Dyche’s Clarets was a dramatic affair, with three goals in stoppage-time sending the tie to an additional 30 minutes. Andy Lonergan’s save to deny James Tarkowski in the shoot-out then sent the second-tier club through.
The triumph at Turf Moor was Leeds’s 11th meeting with Premier League opposition in the League Cup since being relegated in 2004. Eight of those have been lost, the Yorkshire club’s other victories against the elite in this competition having come against Everton and Southampton under Neil Warnock in the 2012-13 campaign.
With a place in the last eight up for grabs, talk of a possible Wembley trip will grow if Leicester, under the temporary charge of Michael Appleton, can be beaten tonight.
“Those are big words,” said Christiansen when asked about the prospect of moving to potentially within 270 minutes of the final.
“But I will try to win all of our games and try to pass as many rounds as possible, trying to do it in the best way for the team.
“If we can progress in this cup, we will do that. But we also have to face the reality that after facing one Premier League team, we are going to face another one. And, if we have the luck to pass to the next round, we will face another and perhaps a very strong Premier League team. It is difficult, but we have to enjoy the moment and the game in front of us.”
The trip to the King Power Stadium comes during a seven-day spell that is book-ended by tough Championship assignments, the first of which was the 3-0 triumph at Bristol City.
Sheffield United are due at Elland Road on Friday for a fourth-versus-third clash that will be shown live and Christiansen may again make wholesale changes to his line-up in the cup.
Against Burnley, only Luke Ayling and Conor Shaughnessy of the side that had lost 1-0 at Millwall the previous Saturday started, while the wins over Port Vale and Newport County brought nine and ten changes respectively.
“It is my responsibility not to make mistakes in the line-ups,” added the United chief, who will be without Stuart Dallas, due to a family bereavement, and the suspended Gaetano Berardi. “The good thing is I have a good squad that gives me plenty of options.
“It is busy all season long. It is not just this week when we face three games in seven days, but everyone is mentally prepared and ready. ”
Asked if he regarded the league as the priority over knockout football, Christiansen replied: “Both the league and cup are important.”
The victory at Ashton Gate was the ideal fillip ahead of taking on the club who stunned football by lifting the Premier League title under Claudio Ranieri at the end of the 2015-16 campaign.
Christiansen, who admitted United’s flight home from Bristol was not a pleasurable experience due to the windy conditions, added: “The win was deserved. Maybe in other (recent) games we didn’t have the luck in front of goal, that is why we lost the games.
“The 3-0 score was the response I wanted, especially as it was their first defeat in Bristol for a long time. We don’t lose the confidence so fast and we don’t get it back so fast. But, of course, it is the beginning of recovering that confidence.
“Confidence comes when they see they do things right and get the results. But I see and I believe that all the players are giving their best to improve and get us in the best position.”
Match preview: Page 18.