#3 Marc-Andre ter Stegen needs a rest
Ernesto Valverde's biggest mistake no doubt is failure to rotate the squad wisely. At this moment, Busquets, Stegen, Rakitic, Pique, Alba, and Messi are not well rested. The fatigue they gather now will reflect in the latter stages of the competition. Among the players, the one who needs a rest most is Barcelona's #1, Marc-Andre Ter Stegen.
Marc is a great keeper, no doubt. He has the ability to play all the games in the season, and doesn't deserve to be benched. But lately, Ter Stegen is showing signs of a lack of concentration. It clearly is not because he is not good, it has to be fatigue.
Ter Stegen showed a lack of concentration throughout yesterday's game, as he misplaced a lot of passes. Being a keeper who distributes the ball with utmost perfection, it is a surprise that he completed only 52 percent passes. He is a great player with his feet, but was able to complete only 14 of his 29 attempted passes.
Against Atletico Madrid, Costa's header had no real power behind it. It was a routine save for Marc Andre Ter Stegen, going by his standards, but the ball went over his hands. Against Betis, he didn't put enough strength behind his hands as the ball went off his hands into the goal.
Being on a cold run of form, Ter Stegen deserves a day off the pitch. He needs time to regroup from the flurry of errors, and also the fatigue he is carrying. He was not included in the Nations League squad for Germany due to a shoulder stress, but Valverde played him because it wasn't serious.
With Cillessen on the bench, there is nothing to worry about even if Ter Stegen is absent.
Just give him a well-deserved rest gaffer!