The Australian got to see the talent in person for the first time as he was involved for Team K League against Spurs in a preseason friendly.
While his Spurs side won the game, Min-hyeok did impress, as he prepares to join Spurs in January.
On the youngster, Postecoglou told reporters: Yeah, look, you know, there's a game of football tonight.
“I was focused on our players, so I wasn't really following the opposition players. When he comes in, in January, we'll have plenty of time to look at him.
“I think what's important now is that we've made the announcement and he concentrates on his club football here in Korea, finishes his season strong.
“He's had an outstanding season so far and then when he gets to us, he'll have plenty of time and plenty of opportunity to show us what he can do and we'll help him with that process.”