He was never that great at defending when the team is being pressured, but leaving him alone without cover against di maria or Bale is torturing an old man...
If he was crossing against coach orders undoubtedly it would be a snap sub, but then Barca wasn't creating anything in the ground before Fabregas was out and there were frequently players positioning as a post-man so I think he was actually ordered to do that...
I've said it all along, it's on command, people who can't see it are clueless. It's not like he's been doing it his whole career. It's definitely something they've decided to do, because Alba is crossing a bit as well, Neymar as well, there's just a lot of crossing to no one going on. Maybe Tata remembered Neymars goal in the Supercopa and decided that it's the way to go...