Bartra's debut for Barcelona was against Atletico Madrid at the Vicente Calderon, he played as a Right back and did well.
Bartra used to play as a RB, CB and DM for the B Team. It won't be his 1st time
Anyway, I don't think Tata will do it and put Alves on the bench against Madrid. But, IMO he should try it... Bartra could be the solution...
The problem is that if we tried it against other Liga teams, its useless. In fact, we need 2 attacking full backs against the likes of Levante, Almeria, Osasuna etc...
The problem is against Real Madrid/Bayern and you can only know if it will work, if you tried it against these teams...