Argentina’s struggles at the World Cup may not come as a surprise to many after a qualifying campaign where they almost ended up missing the bus to Russia. It took a Lionel Messi hat-trick against Ecuador on the last matchday to help Argentina squeeze into the World Cup.One of the biggest weaknesses that the South American qualifiers exposed was the absence of a well-oiled midfield.READ | How Iranian fans attempted to disrupt Cristiano Ronaldo’s sleep at hotelDuring his time as head coach, Jorge Sampaoli has been unable to find a stable set-up in the midfield that can help execute his high-press, attacking brand of football with fluidity.With an attack boasting of some of the world’s finest forwards, there is always a temptation to use as many of them as possible. When Argentina trailed Croatia by a goal, Sampaoli introduced Gonzalo Higuain, Paulo Dybala and Cristian Pavon, taking off Sergio Aguero, Eduardo Silva and Enzo Perez.His refusal to add another midfielder left Javier Mascherano alone in central midfield. The idea of the high-press deteriorated further and aided Croatia’s counter-attacking game.Against Nigeria, a match Argentina must win – and win by a big margin, in case Iceland beat Croatia – Sampaoli can ill-afford to go ahead with a similar set-up.That is why Ever Banega and Angel di Maria could be the key on Tuesday. Nigeria are likely to use the 3-5-2 formation they did against Iceland. For Argentina’s high-press game to be effective against a team that will look to crowd out the midfield, Banega could be important in improving the ball circulation that Argentina lacked against Croatia.READ | Who’ll go on playing longer? Cristiano Ronaldo or Sunil Chhetri?Lucas Biglia will be another option for Sampaoli but the AC Milan midfielder failed to impress against Iceland and is unlikely to be preferred ahead of Banega, who is arguably Argentina’s best playmaking option in central midfield.With Javier Mascherano unlikely to be dropped, playing Banega next to him could also provide more defensive solidity to the side.Di Maria, on the other hand, has in the past excelled playing on the left side of a three-man central midfield. It is a position he often played at Real Madrid under Carlo Ancelotti and later in the national team.With Argentina’s lack of creativity from midfield evident against Croatia, Di Maria’s pace and eye for a pass could be an effective tool in unlocking Nigeria’s defence.After the 1-1 draw against Iceland, Sampaoli had acknowledged the lack of creativity from the midfield. Argentina had struggled throughout the first half before Banega was brought on early in the second half. It helped Argentina create sustained pressure on Iceland and also win a penalty but the winning goal never came.READ | FIFA World Cup 2018, Juan Quintero does the work, James Rodriguez gets the glory“Maybe we needed to be more creative in the first half; perhaps we needed some more through balls from midfield such as the one which led to the penalty,” Sampaoli had said after the game.It remains to be seen how Sampaoli lines up his side on Tuesday but reports in the Argentina press on Sunday evening claimed that both Banega and Di Maria would start against Nigeria. A 3-4-2-1 formation against Croatia had remarkably failed and Sampaoli is likely to switch to four players at the back.