Porter said that it wasn't just the view of himself; but also of everyone around Bennett and that they don't want to rush him.
In addition, he wants Bennett to take his career one step at a time; as well as that he is sure one day he will play in the Grand Slam.
"On balance, we felt it was [too early for him] and that was a unanimous view of everybody who was involved in that conversation - all the people that were around Leighton and everything like that," said Porter.
"There's no doubt that Leighton is a fantastic talent and a huge prospect; but he's 13-years-old, so let's keep everything in perspective. There's no mileage in rushing it.
"Leighton needs to take his career one step at a time and learn to deal with everything in a mature manner and that will be difficult for him if he keeps on getting thrown in at the deep end all of the time.
"He's made huge progress this year and he'll keep making huge progress every year into the future I'm sure and no doubt one day, he will play in the Grand Slam."