I know we criticize our players a lot, but really, we have 2 of the best 10 RBs in the world. No joke.
As for Semedo's game, I liked 3 things.
1) His passing was very on-point in pressure situations. Like, he was pressed near the sideline, and put the ball in the middle several times. You need some balls to do that, because we're talking 30m. passes from wide inside. If that pass is not controlled and precise, it's a big problem.
Those passes don't work all the time for him. Today he felt the ball better.
2) Was very solid defensively, except the cases where he was caught up field (usually due to a fuck-up in build up by Busi or Rakitic). You could see that United players knew his strenght in 1 vs 1, because they didn't try too much, and were happy to put in crosses from far wide without challenging Semedo. He has pace, and is strong. Hard opponent to beat in individual duels, without some great technical skills.
3) He didn't attack a lot, but he actually played a couple of interesting balls, one of which was a near assist. Didn't attack a lot, but didn't waste his few chances either.