Four eyes on one prize
In the other semifinal, the biggest question may be which version of Real Madrid will show up. Will it be the team that was thoroughly outclassed in the first leg of their last-16 tie in Paris, surviving three disallowed goals from Kylian Mbappe and losing 1-0?
With the stage set for the Champions League semifinals, the destiny of the title has been split between four coaches.
The first match-up will see Pep Guardiola, one of the most decorated managers in recent times, line up his Manchester City side against the wiles of veteran coach Carlo Ancelotti and Real Madrid. The duo are among the few to have won Europe's elite competition more than once, although the Italian has the edge with three titles as manager to Guardiola's two.
The second semifinal will see Jurgen Klopp's Liverpool, perhaps the best team in Europe based on current form, take on the only remaining underdogs, Unai Emery's Villarreal.
Although Emery is no stranger to success in Europe, this will be his first semifinal in Europe's elite competition in a managerial career spanning 18 seasons and eight clubs. He may also argue that the Champions League has not been kind to him.
In two years at Paris Saint-Germain, he won seven of the 10 trophies, but was eliminated in the Champions League last 16. The first season, his side faced that famous 'remontada' after winning the first leg 4-0 before a 6-1 defeat at the Nou Camp and in his second season they fell short against Real Madrid.
At Sevilla, he engineered a machine that was the face of the Europa League, winning three consecutive titles but never making the grade in the Champions League. In his debut season at Villarreal last year, he brought the club's first final in its 98-year history, where they dispatched Manchester United after penalties to claim a first-ever trophy.
The fact that he has overseen the dismantling of European giants Juventus and Bayern Munich in this Champions League campaign should bolster the wind in Villarreal's sail further and in Liverpool they have an opponent with a similar style to Bayern.
Against the German giants, Villarreal were far from timid. After pummeling Bayern in Spain but only getting a 1-0 win to show for it, Emery's men were gallant in the away leg, making it a point from the get-go to control the tempo. They played out patiently from the back, absorbing a high press by stringing together intricate passes that saw them keep possession.
Liverpool are almost certain to use a similar high-pressing approach, a hallmark of Klopp's rock-and-roll style of football, but they will know that the obsessive Emery, who claimed to have watched 17 Manchester United games to prepare for last season's Europa League final, will be just as meticulous in preparing against that.
There will be little given in defence and Liverpool will need all the firepower that Sadio Mane, Mohamed Salah, Roberto Firmino, Luis Diaz and Diogo Jota can muster if they are to break through. It is certainly not an insurmountable task for a team that are still chasing a quadruple and have already won the Champions League under Klopp. But it will be one of their more daunting challenges, as Juventus and Bayern can attest.
In the other semifinal, the biggest question may be which version of Real Madrid will show up.
Will it be the team that was thoroughly outclassed in the first leg of their last-16 tie in Paris, surviving three disallowed goals from Kylian Mbappe and losing 1-0? Or will it be the team that overturned that deficit with a Karim Benzema hat-trick in the second leg? Will it be the team that was demolished 4-0 at home by Barcelona in La Liga? Or the side that bounced back from that to defeat Chelsea 3-1 in the first leg of the quarterfinals of the Champions League?
Madrid have not played well throughout any of those games, but in each there were moments when they seized the initiative, especially after going down 3-0 against Chelsea in the return leg.
But despite raising their game at the right time on each occasion and pulling through, their up-and-down performances have left the impression of frailty. It will be nigh impossible to find any such leeway against Manchester City if they let their levels drop, but perhaps a team that has made semifinals in 10 of the last 12 seasons does not need to worry about nerves at this stage.
Perhaps those nerves should be reserved for a team such as Manchester City, who have desperately sought but never won Europe's top prize, coming closest when they finished runners-up last season.
For Guardiola, the quarter-final against Atletico Madrid, particularly the second leg at the Wanda Metropolitano in Madrid, served as a sort of exorcism and could give them the mental edge that such an upcoming encounter requires.
Tormented for years by teams setting up in doggedly defensive shapes -- such as the '5-5-0' that he claimed Diego Simeone's men had adopted at times in the first leg -- he turned the tables in the second leg.
It was the Manchester City players that were killing time, defending deep and urging Atletico to bring the attack to them, all the while winding them up any chance they got. The frustration on the face of Simeone as he protested such tactics and the meltdown his players had in the tunnel after the game was a joy to see for fans of any team that have had to line up against Atletico over the years, but perhaps all the sweeter for Guardiola.
There is little chance that he will set up his team like that again, but knowing that they can dig in to such an extent will be a confidence boost going into their marquee tie against Real Madrid, who themselves are masters of getting under the opponent's skin.
Manchester City
Record vs Real Madrid: P6 W2 D2 L2
UEFA ranking: 2
Tournament best: Runners-up, 1 (2020/21)
This season
Record: W6 D2 L2 G24/10
Top scorer: Riyad Mahrez (6)
Real Madrid
Record vs Man City: P6 W2 D2 L2
UEFA ranking: 5
Tournament best: Winners, 13 (1955/56, 1956/57, 1957/58, 1958/59, 1959/60, 1965/66, 1997/98, 1999/2000, 2001/02, 2013/14, 2015/16, 2016/17, 2017/18)
This season
Record: W7 D0 L3 G22/9
Top scorer: Karim Benzema (12)
Liverpool
Record vs Villarreal: P2 W1 D0 L1
UEFA ranking: 3
Tournament best: Winners, 6 (1976/77, 1977/78, 1980/81, 1983/84, 2004/05, 2018/19)
This season
Record: W8 D1 L1 G25/11
Top scorer: Mohamed Salah (8)
Villarreal
Record vs Liverpool: Liverpool P2 W1 D0 L1
UEFA ranking: 18
Tournament best: Semi-finals, 2 (2005/06, 2021/22)
This season
Record: W5 D3 L2 G18/11
Top scorer: Arnaut Danjuma (6)