Byrne academy chief Alf Ingve Bernsten has recalled having a junior Erling Haaland training with the club.
Bernsten says the father of the Manchester City star, Alf-Inge Haaland, never threw his weight around after enrolling his son, despite his playing background.
He recalled to O Jogo: "From the age of 8 until the growth spurt, there was a constant variation of training with the aim of learning many different body movements. Erling was fast and had good body control from an early age.
"When brutal growth happens (Erling had his at 14 years), we had to let him train less. After that jump, we had to plan the type of training and focus on the balance between training and physical restitution.
"From his genes, we knew he would become fast and strong, so we saw that something very special was happening from the age of 12.
"He smiled a lot, scored a lot and trained even harder. Along with a large group of 40 players from Bryne who did the whole process. He was well behaved and very popular in the group."
On former Leeds and Manchester City midfielder Alf-Inge, Bernsten continued: "He always let Erling train with us, without any pressure. He never told us what to do, he simply let his son grow up alone, with a large group. Later they made smart choices with the chosen clubs.
"Normally, fullness is reached between 25 and 30 years old, so it seems clear that Erling will still improve a lot, not least because he is always breaking records. That makes him special."