Slightly concerned I'm fine with, but some of the comments above sound like outright panic.
Yates was a key component in making the 4-4-2 work and I don't think we've been the same since, so maybe Nolan will have to start looking at changing the formation to suit the current personnel, but there's plenty of time to do that, and we're still talking about the manager who pulled us out of a relegation freefall and led us to 5th last season. Obviously he had the skills to change our fortunes then, so give him the benefit of the doubt and time and see if he can do so again.
Even his overall stats, going back to the day he took charge against Mansfield, would not be enough for automatic. If you include the two play-off games as well as all league games, his average points per game probably wouldn't be enough to make the play-offs (a 73 pts projection). That is to say, he has to improve upon - not just equal - his results since arriving in January 2017. The stark fact is that results have gradually worsened over a long period of time and much of his success (8 wins, more than he's managed this calendar year) was condensed into a very brief period of six weeks last August/September.
I get that Rob but I think its the individual mistakes that cost us time after time, the first goal today was comical but it ain't the first time it has happened, this defense just doesn't breath any confidence in me, Hall coming in might help a little but who do you drop... Bris and Duffy both have more off days than on.