Complete lack of wing play
Barcelona had 11 shots on target in the game, only two of them were on target. Athletic made it very difficult for the visitors to channel balls through to their wide players for the most part in Antoine Griezmann and Ousmane Dembele initially, and Rafinha or Perez once they came on.
The Catalan side is not one that is renowned for lots of crossing from open play, but they usually have some width to open up the pitch. The sight of Jordi Alba bombing down the left and in days gone by Dani Alves on the right is quite familiar to Barcelona fans. But there was no width from the visitors in this game.
When Griezmann or Dembele were on the ball, they drifted inwards. Rafinha also tended to come in when starved of the ball just so he could get involved with play. Normally that would see Alba and Semedo run past them and keep some width in attack, but Athletic's pressing in wide areas kept them from having any impact at all.
Rafinha hit the bar once after his shot from long range was touched onto the post by Unai Simon in probably the closest attempt of the game. Suarez also hit the post from a defensive error from a position where he really should have scored, but apart from those two attempts, Barca never really tested Athletic.