Assuming that the goalkeeping situation will eventually get solved and that Romero will eventually leave Monaco for a team in which he will get sufficient play time, the defense is next in line when it comes to analyzing the team.
The Argentinean defense was never the strongest line in the team, even before the goalkeeping situation became an issue. Sabella took over a national team and started to build pillars. To build a strong team it is vital to have a strong foundation in each line of play, the goal, the defense, the midfield and the attack, and once there is a trustful and strong foundation, the rest of the team can be easily formed around these. Disregarding criticism, Sabella has maintained his team intact during his years in charge, he has only made changes around the pillars he himself had build, and most changes have occurred in the defense.
The full back position is the most questioned one of the team in its present situation. Pablo Zabaleta and Marcos Rojo are the full backs that Sabella will most likely take to the world cup, he has used them the most in the qualifiers, and they are the best that Argentina has in that position, this does not mean they are either good or bad. The problem that Argentina’s defensive backs encounter is when the opposite team has fast wingers who can beat them to the flanks.
It isn’t hard to find full backs that are going to participate in the attack, the problem is their defensive abilities. Marcos Rojo is a young player who is capable of playing left-back and center back, his performances on the national team had been irregular and far from excellent. The same goes for the right-back, Zabaleta, who is known for his great performances at his club, Manchester City, he has yet to prove himself in the national team.
Argentina has had the same problems for years now, there aren’t any more full backs who are capable of shifting in the defensive line, becoming center backs, who are also capable of heading the ball out the box and away from the opposite players. It happened on the 1998 world cup in France, when then left -back Chamot, missed his mark which led the talented Bergkamp to score a magnificent goal. It also happened in 2006, when the Germans headed the ball twice at the top of the big box, tying the game and later winning it by penalty kicks. Maradona tried to avoid this weakness by placing a line of 4 center backs at the 2010 world cup, placing Otamendi as a right-back who failed miserable in every aspect, he looked confused and out of shape. Otamendi has become one of the best center-backs in Europe, the problem wasn’t his form, it was his lack experience on the back wings.
This is an ongoing problem for Argentina, after the great Zanetti there hasn’t been any true backs, Sorin and Placente were great at attacking but not at defending on the counter attack. The solution for the team is to use players who are known to be able to play both defensive positions like Campagnaro and Basanta, and Sabella knows this issue and that why he uses them as alternatives or backups. Clemente Rodriguez, when in form, was the best back available because his first priority was to become part of the defense, he did participate in the attack in occasion but only as a secondary role.