A picture of Grealish inhaling nitrous oxide, taken a year ago, emerged last month and Sherwood wants Grealish to follow Cole's example and stay away from the limelight.
"Joe never got effected by that. I didn't read too much about Joe Cole being on the front pages," he said.
"He's just got to show (Jack) the lead hasn't he - 'just follow me, see what I did'.
"The world has changed because when Joe was coming through I was still playing, so I know what it's like to get twisted up by Joe Cole.