Then the 21-year-old midfielder stamped his authority on it.
Socceroos boss Tony Popovic delivered a huge shock when he picked Okon-Engstler to partner Aiden O'Neill in midfield, ahead of vice-captain Jackson Irvine, for Australia's opening match against Turkey.
At the 22nd-minute drinks break, the midfielder took some advice from one of Popovic's assistants - his father, former Socceroos skipper Paul Okon.
Minutes later, the 21-year-old used his deft left foot to perfection to chip a ball beyond the Turkey defensive lines for Nestory Irankunda to run onto, control and score.
"I know Nestor's capabilities and his strengths, his running in behind with his speed," Okon-Engstler said.
"Obviously we practised that the whole week, just looking up and trying to play balls in behind for Mo (Toure) and for Nestor especially.
"I just saw the opportunity to do it and I tried to execute it to the best of my ability and obviously it was just great that I was able to set up the goal for Nestor."
Okon-Engstler didn't stop there.
The big-bodied midfielder was proactive with his passing range on the ball and relentless off it, at times brushing off Real Madrid star Arda Guler and Inter Milan midfielder Hakan Calhanoglu.
After Connor Metcalfe delivered Australia's second goal, sealing a 2-0 win, former Socceroos teammates Okon and Popovic had an emotional embrace.
"For me, playing his son is special," Popovic said.
"I play him because he deserves to play. I love the kid. I've loved him since, well, 12 months ago when I first brought him in.
"I knew there was a special talent there and he proved it today."
The good news for Australia is Okon-Engstler, a self-described late developer who has shot up and filled out in recent years, should only get better.
"He's a serious player," Irvine told AAP ahead of the Turkey game.
"His technical quality's through the roof.
"He's already got size and he'll get bigger and stronger, quicker with every game he plays, and become more robust - his understanding of the game (will improve) as well.
"He's got a seriously high ceiling."
Okon-Engstler is aware of his unique position as the son of an assistant coach and, in camp, considers his relationship with his father purely a coach-player one.
But some moments are bigger than that.
"After the first goal I ran over to the bench to celebrate with him," Okon-Engstler said.
"He was obviously there and I could see the emotion on his face and that really, really touched me.
"... It was a nice memory for us and it's a memory that I'll cherish."
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