I don't think he played bad today. However, his contribution is immense. During preseason derby with Man City, it was very clear that we dominated. Most of the domination was through center via Mhki. I don't think the problem is the attack but rather the variety of.
This season we have seen more of a threat from wings. More crosses and more cutting in from the sides (not through center). All teams target Mhki. I have noticed he has always at least three around him constantly as he roams. Mata is starting to donthis. I think if you get Greizmann, he will roam as well and it will overload opponent. However, ironically, having more in the center congests the middle. What I think will improve and take pressure away from Mhki (or AG) will be more variety from sides. More width will push opponent to move away from center.
Let's be honest Greizmann against Chelsea was terrible and it is not as simple as throwing AG into the mix as most think the problem is with Mhki. AG is going to face same problem. It was apparent that AG was having same problem against Chelsea. I just don't think it's smart going gung-ho on the AG band wagon without solving the width issue. Matic also was losing possession and making bad passes, honestly, I noticed it one or two times but his other contributions were immense. The other factor is fatigue and when you look at whole team as whole they were just cruising.
End of the day, I just don't think it's smart thinking that Mhki does nothing as we have had many games without him and MU played much worse. Notice, we add a striker that has pace and size and a controlling Mifielder, we are beating teams 4-0. I think adding width will add more value. Any number 10 is going to face the dilemma of limited space. Our attack cuts in centrally and opposition targets center man most often, when you provide more width playing wide and a proper winger, the attack as a whole will improve.