to [bring, knock, take] down a [notch, peg] [or two]
Contexto
"Knives can be out for a second series," he says, his brow furrowing. "Especially when we got so much support for the first series and everybody was just overwhelmingly positive. So next year, regardless of the quality of the show, people will tend to go, “Lets knock you down a peg or two. And that is understandable. But the scripts are strong and the performances are all there, so we have every confidence that we are going to produce something great."
It is not so frequent with the sense of criticising.
We did not find examples, but the dictionary states that it can also be said “to knock down a peg” without “or two”.