Johnson is taking to Di Canio's man-management.
The Italian told the Daily Mail: "There is much more to come from Adam. He has very good quality. I can put him in a position to use his talent, to express himself.
"It is clear what he needs, to be on the ball and he has already started to improve.
"I didn't do a special job on Adam. I kicked his bottom two or three times in training sessions - even at the end of the match. As an ex-professional I can argue with him but there should not be any more excuses. We have to be clear with him.
"We will give him the opportunity to play the right kind of football but he has to work so hard.
"Physically you must work hard in the training sessions all week but otherwise it is a shame. He is 25. Sometimes you hope that the words are enough but more important is the work we're doing.
"He gives everything, he is ready. He has never had a bad mood. Even when there was a very hard session of running without the ball he worked hard.
"Normally the fantasy players they don't want to work without the ball but he was there near the top of the statistics. I was more than happy.
"Credit has to go to him because there was a change and he was ready and capable to take this as an opportunity to improve."