FC Barcelona Tactics: Time for Three At the Back?

Here are some facts.

1. Aleix Vidal is out for the season.
2. Sergi Roberto is not in good form, and seems mentally fed up with the right-back position.
3. Barcelona need a huge offensive display to pull off a miracle comeback against Paris Saint-Germain in the UEFA Champions League
4. Barcelona have 3 starting quality centerbacks.
5. Barcelona have a glut of decent-to-pretty-good midfielders, but no one outstanding candidate besides Sergio Busquets and Andrés Iniesta.

With these facts, isn’t three at the back the logical conclusion?

Barcelona have almost no right-backs, unless a signing is made. Samuel Umtiti is almost too good to keep on the bench. And the team has versatile midfielders.

Sergi Roberto could play either as a wing, or as a central midfielder rather than a fullback.

And there are basically two flavors of three at the back - 3-4-3 and 3-5-2. 3-4-3 has been tried before, with mixed success. It leaves the team open at the back, but that could be a worthwhile risk given the dire situation of the CL tie. Plus, maximizing risk when you’re down in the league table might also be a good idea.

3-5-2 is less radical and could give Barcelona more security, perhaps. Lionel Messi could play as a #10, which, more or less, he is already doing. Albeit now, perhaps, it would be more on purpose as part of the structure rather than as a result of less creativity in the middle of the park.

So, is there any future in this plan, or is tried-and-true 4-3-3 still the best answer?