You basically answered your own question. He'll never play midfield because he takes too many touches of the ball. Everything you are suggesting as a positive to playing midfield is the opposite to what Pep actually wants. His central midfielders need to take few touches and move it quickly, he takes many touches and slows everything down. He has no change of tempo and he actively invites challenges for the ball. now he is generally very good at protecting and drawing fouls from them challenges but again, that's not what you want from a central midfielder, the opposition shouldn't be able to get near the ball if you're doing what Pep wants in there.