I think he is the best we've got as a left-back. Contento, Pranjic, Luiz Gustavo and all the players that have passed on that position (Badstuber included) were not as good as Alaba.
With time and confidence, he will get better against stronger rivals.
Not to mention that he was already playing as a left-back v Germany on the Eurocup qualifiers and he did a good job v Müller. So, why not a good job v others like Reus.
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