Anthony Elanga's 80th-minute equaliser off the bench in Madrid three weeks ago has perhaps tilted this tie slightly in United's favour. Ralf Rangnick's side know we just need to win at home, something we did as recently as Saturday when Cristiano Ronaldo scored a stunning hat-trick to down Tottenham Hotspur.

As the Portuguese centre-forward scored the 805th, 806th, and 807th goals of his career, a raucous Old Trafford crowd responded in jubilation. The full-time whistle against Spurs signified a crucial victory in the race to finish in the Premier League's top four. But attention very quickly turned to Atletico, the reigning Spanish champions, and their visit to M16.

The much-anticipated team line-up will be released at exactly 18:45 GMT - 90 minutes ahead of kick-off - and you can get it hot off the press via the United App, ManUtd.com, MUTV and our social channels. Don't forget to make your United Predictions, either, for the chance to win a signed shirt.

Rangnick told reporters in his pre-match press conference on Monday afternoon that he has a fully-fit squad to pick from, with the exception of a "small question mark" over Luke Shaw. That leaves the German coach with a selection dilemma. So, what team is Ralf going to go with?

With a fully-fit squad, Rangnick has the luxury of several options to choose from. In recent weeks, United have elected to play without a recognised striker due to injury, but that won't be needed this time. Ronaldo is fit and firing and Edinson Cavani came off the bench on Saturday for his first appearance in a month.

The first real question is about the midfield. In the first leg in Madrid, an Atletico trio of Kondogbia-Llorente-Herrera caused United some damage, their energy and pressing making it difficult for the Reds to play out. That will be perhaps the key area of the pitch on Tuesday. Against Tottenham, Nemanja Matic put in an impressive performance at the base of a midfield three, his composure allowing Fred to assume a more advanced role, where the Brazilian excelled. Paul Pogba was the other midfielder, and with Scott McTominay now available again, could he come back in?

In attack, Ronaldo made his mark on Saturday, Marcus Rashford showed some good signs and Jadon Sancho's excellent, and productive, form continued. Anthony Elanga showed his quality in Madrid and will be an option, and Bruno Fernandes, who missed the weekend's fixture, is back. There is plenty to think about.

Let us know what you'd do by voting in the poll above. But before you do that, check out these hot takes from three of our United-supporting staffers...

AN UNCHANGED XI?

"Ralf Rangnick spoke in his matchday Q&A this morning about how the short turnaround between Saturday’s win over Tottenham and this evening’s tie with Atletico was “not much of a problem” and therefore there is a case for our interim manager potentially naming an unchanged XI later, despite the fresh reinforcements that have been welcomed back since the weekend.

"The line-up that started the victory over Spurs was one that was able to power us to arguably the most important triumph of Ralf’s short tenure so far, and with no fixture to follow until April, that same group will no doubt be electrified with confidence and ready to get a result of a similar nature again tonight, if called upon, with rotation likely to be less of an issue when selecting the side due to the upcoming break.

"If the boss is to make a few alterations, however, I wouldn’t be surprised to see Anthony Elanga and Bruno Fernandes return from the start, having linked up so well for the goal in the first leg, but I think the team could be largely unchanged otherwise, if not completely the same as we saw three days ago."

- Mikey Partington

THREE RETURNING PLAYERS

"Ralf explained there remains a 'small question mark' over the availability of Luke Shaw for tonight's game, but that Scott McTominay and Bruno Fernandes are fit again. All three are regular starters in Rangnick's United teams and should return to the team this evening. Shaw's quality last season was recognised across the world and although this season hasn't seen quite the same level of consistent quality, he can be relied upon to provide the right balance of attacking quality and defensive solidity from that left-back position.

"Bruno Fernandes's stats speak for themselves. He's assisted in every UEFA Champions League game he's played this season and he has the quality to win a game in a moment. Against Atletico's low block, that'll likely be needed. If I were Rangnick, I'd try and keep Bruno as high up the pitch as possible, as we saw tried in the first half against Manchester City. It's there that his quality really counts, for several reasons. First of all, he can be a great focal point for United's defence and midfield to play to. His touch is good, as is his awareness. Secondly, it allows him to start attacks quickly with players running off him, and thirdly, his energy high up could be important when Atleti try to get a hold of the ball. Cristiano Ronaldo is not a high-energy presser - we all know that - and Fernandes can be.

"Finally, Scott McTominay can come back into the side. These games are made for him. He raises his performance to match the occasion and enjoys the challenge of a high-pressure match. We've seen impressive performances in Europe from Scott, with his driving runs making him the stand-out player in last year's UEFA Europa League final defeat. This is our biggest game of the season, and McTominay is one of those players who you can rely upon to understand the magnitude of the night. He could be key."

- Harry Robinson

ARE SUBSTITUTES THE KEY?

"Whatever line-up Ralf goes for tonight, it's almost certain we're going to need much more than the 11 starters.

"The first leg was turned by Rangnick's second-half substitutions, with Elanga, Matic and Telles all proving really influential. And it was interesting to hear the thoughts of John O'Shea conveyed via the latest episode of the Talk of the Devils podcast. The Irish stalwart noted that several United players looked out on their feet after the 3-2 win over Spurs - an exhausting game that barely stopped see-sawing for the entire 90 minutes.

"Whether Ralf changes the starting XI, or we need fresh impetus at half-time or in the second half, I feel subs are going to play a vital role against an obdurate Atleti side that are renowned for keeping games tight. Heck, is it too early to start thinking about bringing on specialist penalty takers during extra-time? I'll leave it there, because I'm making myself far too nervous. But my prediction is that substitutes will have a big and possibly decisive effect on who progresses to the next round. So don't get too hung up on who is and isn't in that much-anticipated starting XI around 19:00 GMT tonight."

- Joe Ganley