We're missing two of our key players in Blind and Di Maria.
Carrick is being expected to bring the ball out of defence, keep possession, find some space and play the incisive balls all in one go. Good as he is, he is not good enough to do all that, especially at 33. He stays in midfield and is not running into space to put passes on a plate for our defence, who are so unsure on the ball that they need it on a plate. Because they don't have that option, they're passing it amongst themselves or aimlessly belting it forward. Blind drops back and can keep possession under pressure better than Carrick, allowing Carrick to find himself the space to receive the ball from Blind and play it forward.
Di Maria is our one player who everyone bricks it when he's on the ball. He creates space for others purely by being there, not to mention his pace.