Diego Simeone is considered as one of the world's best managers for his work at Atletico Madrid over the last decade.
Atletico have been unable to compete with the financial muscle of Real Madrid or Barcelona, but through Simeone's work, they have earned their place among Europe's most elite clubs. It has been achieved by determination, tenacity and great tactical nous.
Simeone has led Atletico to two La Liga titles, the Copa del Rey, two UEFA Europa Leagues, two UEFA Super Cups and to finishing runner-up in the Champions League twice. They've won hearts along the way, heading into games with an 'underdog' status - Atletico ironically spent £110m on Joao Felix in 2019 - which has somehow survived despite their club regularly contending for major honours.
That status has likely survived because of their defensive style of play and the fact that they compete in the same league as Real Madrid and Barcelona. It has served them well, Atletico won the La Liga title last season, for example, but there's a feeling that's hard to ignore in Spain that Simeone's 11-year reign is now coming to an end, which is good news for Manchester United.
United's Champions League campaign has been a rollercoaster ride. Although United booked their place in the knockout stages of the competition with one game to spare, their group stage was far from straightforward. Cristiano Ronaldo scored two late, dramatic goals to earn points against Villarreal and Atalanta while United had to fight from two goals down at home to the latter.
United have endured a tumultuous season and progressing in the Champions League wasn't as simple as it appeared.
With Ralf Rangnick in charge, United will travel to Atletico Madrid on Wednesday night in the first leg of the Round of 16 in the competition. It will be United's first visit to the Wanda Metropolitano, which is hardly a stadium that gives the underdog impression.
United are out of the Carabao Cup and the FA Cup, they never looked like challenging for the Premier League and the Champions League is their only remaining avenue for silverware. It seems they need would need a miracle to win Europe's most elusive prize, but they should be confident of making it to the quarter-finals. Atletico have arguably been worse than United this season.
After winning La Liga, Atletico have had a nightmare campaign. They sit fifth in the table, they lost to Levante, who are at the bottom of the relegation zone, in their penultimate fixture and they could be without key personnel for Wednesday's match.
Considering that, it wouldn't be surprising if reports of Simeone tinkering with his tactics for United's visit are true. Spanish media have 'leaked' that Atletico have trained with five at the back this week and Rangnick's side could find that difficult to play against.
It's no coincidence United always look dangerous against Leeds. Marcelo Bielsa's side are chaotic and leave space to exploit. Atletico, especially if Simeone plays five at the back, will be the opposite. United will have to devise a plan to break them down.
United can often look devoid of creativity against such opposition that play deep and invite them to attack, but they've got Jadon Sancho for this fixture and he could make all the difference. United will need to break through Atletico's lines of defence and the key to this will be orchestrating quick interplay around the 18-year box. They will need to be smart and inventive in tight areas.
Sancho is United's best player for this scenario. The 21-year-old has averaged more passes, more successful passes, more key passes and more received passes per 90 in the Premier League than Marcus Rashford, Anthony Elanga and Ronaldo this term.
If United want to find a way through Atletico, it seems Sancho will be their most important player.
Rangnick is bringing out the best in Sancho and he's now delivering on his promise after a tricky start to his United career. Sancho has performed well in the Champions League with Borussia Dortmund and he could be a genuine game-changer on Wednesday.
Sancho recorded two assists at the weekend and he'll certainly be ready for that challenge.
