Scotland international Fletcher is close to making his comeback after five months out with a serious ankle injury.
Di Canio is happy with Fletcher's recovery, but will not gamble with the player's long-term fitness.
"If it depends on Steven, he can play now," said Di Canio. "He says 'I can score; I can score; every game I can score now'.
"I can understand him but we have to be sensible, we have to be intelligent. In my opinion it's better to take another week after a few months out. Too accelerate him too much now would be very, very stupid. I tell him it's for you, it's for us.
"I'm very happy. The staff are very happy. He will finally join the group in the next few days and start training. Not full sessions, but practice with the team when we have technical and tactical moments."