Both coaches have plenty of tactical decisions to make due to injuries to key players, and their Tuesday lineups may not reflect what we see for the rest of the season. Let's try to guess which starting XI Luis Enrique and Unai Emery decide to use.
Projected Barcelona XI (4-3-3):
Alves - Pique - Mascherano - Mathieu
Rakitic - Busquets - Iniesta
Messi - Suárez - Pedro
While this lineup is very close to Enrique's favorite group of starters, he has two very important absences: left-back Jordi Alba is out with a hamstring injury, and his backup Adriano Correia is also battling physical problems. The most logical way to go is using Jérémy Mathieu in that position, which is something Lucho used during the preseason. Being a full-back is not new to Mathieu either, but after a whole season of playing as a center-back, he may be a little rusty.
The most important absentee, however, is superstar striker Neymar Jr. The Brazilian was diagnosed with parotitis, and the disease will sideline him for two weeks. Thankfully, Enrique is not short on attacking options with Pedro Rodríguez still on the squad despite rumors of a move away from Camp Nou. But Pedro is not Neymar, and Messi and Suárez will need to be at a high level to maintain the level of the striking department without the 'N' of 'MSN'.
Projected Sevilla XI (4-2-3-1):
Mariano - Coke - Krychowiak - Tremoulinas
Iborra - Banega
Reyes - Konoplyanka - Vitolo
Things could not be harder for coach Emery. After a wave of transfers and a big squad transformation, Sevilla has been hit with plenty of injuries, most of them on defense, perhaps the most critical part of a scheme for a match against Barcelona. All three top center-back options, Adil Rami, Timothée Kolodziejczak and Daniel Carriço are all out, which forces a total reshuffle of his defensive system. Midfielder Krychowiak and right-back Coke will need to fill in in the middle, and that means backup players will have to play on their original positions, which weakens the side.
Luckily for Emery, his offense is somewhat untouched, with prospect Konoplyanka set to play and show his potential. After a injury scare, striker Ciro Immobili is ready to go, and could feature.
But if the defense can't hold its ground against Barça's powerful attack, those offensive options won't be able to do much.