I remember some moments from a game when he was playing with Schweinsteiger. The first moment, Schweinsteiger was between the center and left side of midfield, and played the ball to Shaw moving up on the left. The moment the ball left his foot, he angled to Depay and moved a little bit forward, while looking to his right. He was already completing the triangle and continuation before it happened.
Later in that game, Schweinsteiger was at the right midfield and wanted to play to Herrera coming from the center. There was a player between him and Herrera. Herrera's body language was like "hey I'm covered", but Schweinsteiger nodded forward like "Just take a few steps forwards and the angle is there". Herrera didn't get it, Schweinsteiger himself moved forward and created the angle and played to Herrari.
Disregarding his fitness issues and not fitting in the team, Schweinsteiger was the best player in that team. Misunderstood, because after the game he was criticized for slowing the game down in moments such as with Herrera.
My point is, Herrera doesn't have that football intelligence. He gets the ball, sees a team mate and passes. That's it. He started as an attacking midfielder, the one to give that last pass, and he was not good enough. He didn't make it in the center as well. And now we have a defensive midfielder without body or pace or sophistication.
I agree he can win a ball and give a pass. And despite what I said, he is a good player. For Everton or Athletic Bilbao though. Not for a club like Manchester United, they should aim much higher.