Well, no need for speculation - Moysie himself has admitted he got it wrong in a piece on BBC. The plan was to take Fellaini off after an hour if the score was the same, on the grounds we had lost 2-0 leads before or come back from 2 down. I think on this he was far too cautious. While Fallaini has been doing well, especially scoring a few goals, it's Arteta making the team tick for me, so hopefully we will be ok without Fellaini for the derby games.
I agree that Arteta is in fine form but we will miss Fellaini because of his great nuisance value. I honestly believe that he was wrongly awarded a yellow for raising his foot for the person he was said to be fouling was approaching him out of his eye line. I suspect the ref. was looking to present him with a yellow, unfortunately. We can only hope that we can stay resolute in defence and midfield whilst Fellaini is absent and perhaps we might be able to find someone to take his place.