Di Canio believes Wickham needs a slap in the face to motivate him to reach his full potential.
"Maybe, with this guy, I have to slap his face a little bit," Di Canio said.
"I'm talking about motivating him in a genuine way because he has so much potential. But sometimes he comes in (to training) and he seems to be looking around saying: 'Where am I?' I want to say: 'You are on the football pitch, with the grass.'
"He is an intelligent guy, but once he seemed to be complaining because it was wet. I told him that is typical for this area. Maybe if he doesn't go out in a small t-shirt when it is wet and cold, he won't be complaining. I have told him: 'No small t-shirts.'"
Di Canio has urged him to concentrate on football if he wants to live up to the reputation he brought to the club.
The 44-year-old added: "I don't want him to be missing a couple of games because he is a Playboy model. We are footballers, that is our job."