Thought he acquitted himself well today. Some people will erroneously compare him with Carrick in a deep lying role and that's kind of unfair because Herrera is a natural #8. It's almost like penciling Iniesta in Busquets' position or Fabregas in Matic's position and contrasting the relative difference in performance. A drop if inevitable.
Part of the reason Ander does so well further up is the presence of Carrick behind him, and Mata sideways. Both of them are likeminded technical footballers who operate on a similar mental wavelength. Today, not only did Ander have to tone down his more offensive instincts in favour of defensive workrate in deeper positions - he had to basically shepherd the center of the pitch in a patchwork midfield.
Overall he did his job, which was primarily to monopolize possession - 130+ passes, 90 % accuracy, 5 tackles. Can't complain really. Looked positive and proactive, and threaded a few neat passes through.