Alex Keble picks out four key battles ahead of the second legs of the Champions League round of 16 ties...
"Neither have the agility to avoid being overwhelmed by the piercing Leipzig midfield and the interchanges among their front three."
RB Leipzig v Tottenham (agg 1-0)
Live on BT Sport 2
Tottenham's midfield was hopelessly overrun in the first leg, Jose Mourinho's 4-4-2 leaving big spaces in midfield for RB Leipzig's inside forwards Timo Werner and Christopher Nkunku to drop into. Julian Nagelsmann's 3-4-3 builds quickly through the centre of the pitch, meaning Tottenham need three in the middle to hold firm.
They almost certainly won't be strong enough, given how dreadful they were in a 5-2-3 against Burnley. Mourinho is highly unlikely to isolate his central midfielders like that again, but even reverting to the 4-2-3-1 used in the second half will create the same problem. Injuries and low confidence suggests that, best case scenario, Eric Dier and Tanguy Ndombele together at the base.
Neither have the agility to avoid being overwhelmed by the piercing Leipzig midfield and the interchanges among their front three. Spurs will look to sit deep, keep the score at 0-0, and go for a goal in the final 15 minutes. It's a strategy that cannot function when the difference in quality between the two sides is so stark.
Valencia v Atalanta (agg 1-4)
Live on BT Sport 3
The first leg of Atalanta versus Valencia went exactly as we anticipated, and the second leg should be much the same. The complexity and dynamism of the Italian side's 3-5-2, with its mixture of intelligent possession football in neat triangles and sudden breaks in behind the opposition defence, will again disrupt this flat, error-prone Valencia team.
Their 4-4-2 shape is completely ill-suited to the tie. A two-man midfield is easy for Atalanta's three to overwhelm, particularly with both strikers dropping off into the half-spaces to further give them a numerical advantage. Valencia were torn apart in the 4-1 defeat in Italy and, chasing three goals, they will be even more open in midfield and in defence.
Alejandro Gomes and Josip Illic should drop into spaces to combine effectively, although with such a big lead to protect Gian Piero Gasperini's side are likely to sit deeper and play with greater caution. It won't be such a high-scoring game, but Atalanta still ought to win on the night.
Liverpool v Atletico (agg 0-1)
Live on BT Sport 2
The pattern of this match will be very similar to the one in Madrid, where Atletico's aggressive midblock 4-4-2 pressed the Liverpool midfield superbly, stubbornly refusing to drop too deep and allowing the centre-backs time on the ball before squeezing the central areas. The big difference, of course, is the Anfield crowd. On home soil Liverpool should be better at forcing Atleti back, but only if the full-backs are on form.
The raking diagonal passes between Trent Alexander-Arnold and Andrew Robertson can stretch Atletico wider, creating space centrally, and potentially catch them overloading one flank. The switch could bring either Sadio Mane or Mohamed Salah into the game, allowing them to square up a full-back.
Two pieces of clumsy defending saw Atletico draw 2-2 with Sevilla at the weekend. They aren't as difficult to score against as they once were. With Liverpool dominating the ball and no doubt feeding off the atmosphere, they should be able to score the early goal to set them on course for qualification.
PSG v Dortmund (agg 1-2)
Live on BT Sport 3
Paris Saint-Germain's main problem in the first leg was that Thomas Tuchel switched from his successful 4-2-2-2 to a 3-4-3, and without practice in this formation the French side couldn't muster tempo or intelligence in their attack. Dortmund's midblock 5-4-1 compressed the space superbly, staying deeper than they usually would to make central midfield too congested for PSG to find their rhythm.
That will happen even more so in Paris, meaning PSG's fluid front three will find themselves crowded out. However, it is probable Tuchel will use his attacking 4-2-2-2 for this one as they look to chase the game... which is arguably even more vulnerable. Dortmund's narrowness and diligent organisation means the square shape of the PSG attack will be neutered.
More importantly, playing a back four would leave PSG open to Dortmund's blistering counter-attacks. Their transitions in the first leg were outstanding. It scarcely matters that PSG have scored 13 goals in their last three games, because Jadon Sancho, Thorgan Hazard, and Erling Haaland will find space on the counter-attack as the hosts get more and more desperate for a goal.