Centre-half Morrison has been sidelined for approaching two months with an ankle problem, whilst Green (knee) and Gunning (knee), have been out long-term since October 2013 and August 2014 and respectively.
All three are now in full training and have suffered no side effects.
"Green and Gunning have been training and they have been fine," said the Blues boss.
"Obviously they have been out for a long time so sometimes it's not a quick road back to full fitness.
"They will both play a part in the U21 game coming up early next week, Ipswich at home at St. Andrew's. That is going to be important for them to get some minutes on the pitch.
"Michael Morrison has trained for a week, in terms of fitness he has obviously not missed quite as much - but he has still been out for six weeks so it takes a little bit of time to get that sharpness back.
"To all intents and purposes they are all available for this weekend. I probably feel it's a little bit too soon for any of them but we have got that opportunity, which great for us."
With the pairing of Jonathan Spector and Rob Kiernan doing so well as the central defensive partnership, Rowett does not have to rush Morrison back.
"I think he needs some minutes on the pitch and if he doesn't feature this weekend then he is going to need some minutes on the pitch before the Rotherham game," added Rowett.
"There are two U21 games before that. We play Palace the week after as well. That game is on the Tuesday, with our game being on the Friday. That's a little bit closer than I would like, but certainly there is an opportunity for him to play games."