Johnson has made it clear he is in favour of Di Canio's hardline approach if it brings about an improvement in results.
Under Di Canio, the Black Cats took eight points from their final seven games this season and finished 17th in the table.
Johnson, quoted by the Northern Echo, said: "He's come in, and managers have new things that they want to do.
"The gaffer is big on discipline and if it means us getting more wins, I'm all for it.
"There's nothing worse than losing game after game after game after game all season. I haven't been used to that in my career, so it's been difficult.
"It's been poor, very poor, I think. The table doesn't lie. I think the only thing that we can say is that the only way is up for us now. We can't get any lower to be honest.
"We survived, and now next season all we can do is progress. That's the positive way of looking at it."