To be fair to those people who are concerned about Rojo at right back, their concerns aren't baseless. Whenever I've seen Rojo defend as a left back, more often than not, he's looked to charge at the player he's marking immediately rather than direct him to a less dangerous area before winning the ball. Too often have I seen him charge at the ball holder too soon/be flat-footed in his defending as a left back. At times, he does defend against the ball holder properly, directing them to a less dangerous area before winning the ball, but more often than not, he decides to try to win the ball immediately as a left back, which, more often than not, leads to a dangerous situation if it doesn't go well. I've seen this happen in the Copa America as well several times, further highlighting this fact.
However, when he's not defending against a ball holder, his positioning and awareness of what's going on around him is top notch. He knows what happens around him, and he can sense dangers quite well. His decision-making may have looked bad with us at times last season, but otherwise, his decision-making is normally quite good, and he's very good at suppressing the dangers. This is why I'd prefer him to be a central defender than a left back. His defensive nous and sense is much better utilised as a central defender than as a left back where man-marking is of a greater importance. This was especially well-highlighted against Paraguay, when Argentina's midfield defended poorly as well as Otamendi, whilst Rojo did very well in preventing Paraguay from exploiting the weaknesses on the left side.
I really think he can do very well as a central defender. He may be a bit too rash at left back, but as a central defender, his composure, defensive nous, and decision-making can make him a tough defender to get past.
at people saying he isn't a left back.