It's in interest of both the club and the player not to start him at Mestalla. Playing as a defender in the Barca System is not easy and you need to be in perfect understanding with your team mates. In a possession style like Barca's a wrong pass from a defender could be all it takes to concede a goal. Against Valencia's counter attacking style the least thing you need is a misunderstanding between defenders. From what I have seen from him in the videos he seems to like making adventurous forward runs and tries some risky passes which often result in giving the ball away and that's exactly what you need to avoid against a counter attacking team. He also doesn't seem to have the speed or the agility to stop a counter attack, neither does Pique but at least he can rely on his experience and positioning.
It isn't the best interest of the team to start Busquets who is a proven horrible CB even when he was younger and faster than he is now, it isn't the best interest of the team to lose our best midfielder in a game like that, it isn't the best interest of the team to play injured Digne at CB when he barely played the position, it isn't the best interest of the team to risk long term injury of Pique which would force Mina to be starter in even more important games with Vermaelen being unreliable in terms of staying healthy.
You keep repeating same logic again and again but you fail to answer who can play the position, since Mascherano Barca has failed to use any non-cb into the CB position. Adriano,Song & Busquets were all epic fail. Hell even b4 Mascherano; Abidal & Yaya played CB in their career b4 Barca and that is why they were used in that position. Only CB who came close to being awful as the other "trials" was Fontas, even Bartra was way better than any of Busquets/Sogn/Adriano experiments.
What if he is one? Nobody knows how he would perform on this level.
Big games are good opportunities to shine but there is also the chance of making a mistake that would be remembered for a long time like the famous Bartra-Bale one for example.
Barca fans treated Bartra well after the Bale game, even after the horror show he had against Bayern Barca fans tried to see the best out of him actually. I would take Bartra/Marlon over Busquets as CB any day of the week.
If he proves bad today it is good, it means he will know he has to learn and work harder. Unless he is mentally fragile who would be broke by a bad game, in which case I won't care that much either because that means he isn't made for us anyway
