Barcelona's new coach, Spaniard Quique Setien, attends a training session at the Joan Gamper Sports City training ground in Sant Joan Despi on Jan 18, 2020. (LLUIS GENE / AFP)

MADRID - FC Barcelona coach Quique Setien faces another test as his side face Liga Santander strugglers Leganes in the last 16 of the Copa del Rey on Thursday night.

Barca go into the game after three matches with Setien in charge, during which the players have shown few signs of adapting to the coach's ideas of total possession football and a three-man defense.

Barca go into the game after three matches with Setien in charge, during which the players have shown few signs of adapting to the coach's ideas of total possession football and a three-man defense

After having 80 percent of the ball and struggling to beat Granada and Ibiza, Barca lost 2-0 in Valencia on Saturday, despite having over 70 percent of the ball, but failing to create chances, while the defense (and especially the attacking full backs) were caught out of position by Valencia's speed on the break.

Questions are already being asked about whether Setien was the right man to replace Ernesto Valverde in the dug-out and Ronaldo Koeman has already been touted as a possible replacement in June if things don't work out.

Setien is known to stick to his ideas, but the press in Spain speculate that the players could try and convince him to return to a more conventional 4-3-3 formation, which would see Jordi Alba able to attack space in front of him on the left, while either Sergio Roberto or Nelson Semedo play on the right.

Antoine Griezmann was the hero in Ibiza with Barca's two goals and he is likely to continue in attack alongside Leo Messi, while Ousmane Dembele could play some role after recovering from his hamstring injury.

READ MORE: Four things to look out for in Spain's Matchday 21

Leganes are still mired in the relegation zone, but have improved vastly under Javier Aguirre and drew 0-0 away to Atletico Madrid on Sunday. Their organized defense will make things tough for Barca and Setien's men will have to improve if they are to pass without problems.

Meanwhile Barca are on the verge of selling winger Carles Perez to Roma and are still scouring the market for a replacement for the injured Luis Suarez, with Valencia's Rodrigo Moreno the favorite, despite having totally different characteristics as a player to the Uruguayan.

Barcelona's French forward Antoine Griezmann controls the ball during the Spanish league football match Valencia CF against FC Barcelona at the Mestalla stadium in Valencia on Jan 25, 2020. (JOSE JORDAN / AFP)