Roberto Firmino, Cedric Bakambu with crucial roles in Villarreal vs. Liverpool
Liverpool's Europa League semifinal against Villarreal will be Reds manager Jurgen Klopp's biggest tactical test so far. While Klopp overcame his former side Dortmund in a thrilling quarterfinal, that victory felt more about emotion and passion than tactics. Liverpool were outplayed for long periods. It was hardly a template for success.
Villarreal are a well-organised, compact and speedy side, with coach Marcelino preaching a philosophy comparable to that of Atletico Madrid or Leicester City. They might not see much of the ball, but their counterattacks will be extremely dangerous. Klopp must be cautious in the first leg, and be wary of pushing too many players forward.
Here are three keys battles:
1. Cedric Bakambu vs. Liverpool's centre-backs
Villarreal's main goal-scoring threat will come from their Parisian-born, Congo international striker, Bakambu. A revelation in his debut season with Villarreal, Bakambu has notched twice as many La Liga goals as any of his teammates despite often being a substitute, and has contributed nine goals in nine Europa League starts too.
Bakambu is extraordinarily quic, and utilises this exceptional pace by making a series of intelligent runs into the channels, particularly in the inside-left position. Whereas Villarreal became renowned for their intricate possession football the last time they reached this stage, in 2010-11, Marcelino concentrates more on quick counterattacking -- and Bakambu is the best example of their attacking moves.
Rarely moving short toward play, he instead stretches the game by playing on the shoulder of the last defender. Occasionally clumsy with his first touch, he's nevertheless a nightmare for opposition centre-backs to play against.
He has formed a particularly good partnership with Roberto Soldado, who hasn't rediscovered the goal-scoring form of his Valencia days, but has nevertheless played a supporting role effectively. He has recorded more assists (11) than goals (eight) in La Liga and the Europa League this season, the majority setting up Bakambu for tap-ins from the penalty spot.
Bakambu's pace could be a serious problem for a Liverpool. Klopp's side play with a relatively high defensive line, and are also hampered by the absence of Mamadou Sakho, who the club are refusing to select after he failed a drug test last month, despite the fact that he has not actually been banned.
Klopp, therefore, must choose between Kolo Toure and Martin Skrtel to play alongside Dejan Lovren. Neither represents an ideal option against such a dynamic, explosive runner, and considering the way Bakambu gave top-class centre-backs Sergio Ramos and Pepe such problems in a 1-0 victory over Real Madrid in December, he could prove extremely dangerous against a weaknened Liverpool backline.
2. Bruno Soriano vs. Roberto Firmino
Bruno is the holding midfielder every manager wants. A sturdy, dependable and positionally excellent screening player who intercepts through-balls and dispossesses opposing No. 10s excellently; he's also impressive in possession.
In keeping with Villarreal's tactical evolution, Bruno has changed from a holding midfielder who keeps his distribution simple, to a deep-lying playmaker capable of playing crucial balls. He's more Sergio Busquets than Xabi Alonso, someone who slides clever straight passes into the feet of centre-forwards, rather than knocking extravagant diagonal balls into wide areas. Liverpool must prevent Villarreal's captain from dictating play.
That means Liverpool's counterpressing will be particularly important. Villarreal look to feed Bruno immediately when they win possession, and Liverpool will be forced to crowd him at transitions, preventing him from turning and hitting quick passes into attack. Soriano is clever at varying his position, though, and is capable of dropping back between his centre-backs to start moves from a deeper position, away from opposition challenges.
The Liverpool player in closest attendance will be Firmino, a dynamic attacker renowned for his contribution in the final third. Here, however, his primary task will be defensive, about sticking to Bruno and ensuring Villarreal become disconnected in possession. Their defenders are comfortable on the ball and capable of hitting long passes for Bakambu, but eliminating Bruno from the equation will make Liverpool's task so much easier.
Firmino also needs to contribute in an attacking sense, of course. He's likely to play as a half-forward here, springing forward past Bruno and into goalscoring positions. It will be a demanding role physically, and it wouldn't be a surprise if Firmino didn't last the 90 minutes -- but his role in setting the tempo of Liverpool's pressing could be vital.
3. Mario Gaspar vs. Philippe Coutinho
Coutinho started this season poorly, and endured an injury-interrupted winter when suffering hamstring problems, but since returning at the start of February, he has been in fine form. The Brazilian is often too optimistic with his shooting from long range, offering among the worst conversion rates in the Premier League, but he found the target five times in his last six starts, his best goalscoring run for Liverpool.
For a player renowned as a fine creator, however, Coutinho has rarely played decisive passes this season; it's difficult to remember many occasions he has unlocked opposition defences with the through-balls that became his trademark shortly after joining Liverpool midway through 2012-13. In a tight, tense, tactical, two-legged tie, this would be an ideal moment for some creative genius.
Coutinho's game depends on drifting inside from the left flank into the No. 10 position, but here his defensive duties are also important, as he'll be up against Villarreal's rampaging right-back Mario Gaspar, among the most effective full-backs in La Liga this season.
Mario is the classic Spanish full-back: technically skilled and attack-minded without being defensively negligent. He's more about intelligently timed overlapping runs rather than a permanently aggressive starting position, and will charge forward at opportune moments, specifically when he realises Coutinho isn't in a position to track him.
With tricky winger Denis Suarez set to start on the right flank, the last thing Klopp needs is his own Spanish full-back, Alberto Moreno, being overloaded by two dangerous attacking weapons. Moreno might receive support from a central midfielder getting across to shield him on occasion, but Liverpool also need Coutinho to be disciplined at El Madrigal.
Michael Cox is the editor of zonalmarking.net and a contributor to ESPN FC. Follow him on Twitter @Zonal_Marking.