Everything needs to be viewed through the lens of the cap, of course, but this would be so disappointing to me. Mena played some really strong games at the end of last year. Though I've seen mentions of Bravo playing CB, my sense is he is a natural DM and we desperately need help there. I think Mena has meaningful upside, so it would be a shame to give up on him so quickly.
I agree, but in this scenario, he just lost the job to a Boca Juniors bench player who's primary position isn't even center back. If Mena can't even prove he's better than Bravo, Hernandez, and White in camp, that doesn't bode well for his potential, does it? He's not 21 with unlimited upside, he'll turn 27 in June.
Best case is Mena and Brillant play like they should and win the job, while Bravo comes in and backs up both CB spots and comes in off the bench for Pirlo to protect leads.
EDIT: I forgot about Ivanov in this discussion too. He might really be the one Mena is competing with.