Sterling made a fantastic start to life in the first team at Anfield and only Steven Gerrard and Luis Suarez have played more games for the Reds this season than the 18-year-old.
"This is a kid we're talking about, so we have to take a wee step back," Rodgers told The Mirror.
"The zip has gone and that's down to fatigue. But was that to be expected? Yes it was. I was talking to him the other day about this, and if he didn't kick another ball this season he's had a good one."
Sterling has made 36 appearances for Liverpool this season, scoring twice.