After undergoing hamstring surgery in November, the summer arrival from Burnley has returned in recent games and struck twice in Thursday's Europa League win against AZ Alkmaar.
“He’s pretty quiet, unassuming, but one of these guys who always has a smile on his face,” Postecoglou said on Friday. “He’s very popular in the dressing room.
“The lads felt for him this year, because when you’re training with someone and you see the potential, because he’s exciting, when he gets the ball, he does things that others really can’t do, in running with the ball and taking players on.
“Everyone felt for him (when he got injured). He got a move to a big club, this was going to be his time. He got the injury and the second one was worse. Whenever you’re having surgery or something major like that during a season, particularly your first season in a new club as a young player, it’s tough.
“But I get the sense with Wilson that under that quiet unassuming nature he’s a pretty determined young man. He knows where he’s heading, he’s really ambitious. I was super pleased for him last night, obviously two goals, but just his general play, his link-up play.”
Postecoglou added: “I know the goal they scored was a stuff-up, but don’t underestimate that he ran close to 70-80metres as a winger to intercept that ball. That doesn’t go unnoticed by his team-mates.
“They know that this guy is working hard for the team. It’s not just when we have the ball, when we don’t have the ball he’s bought into what we’re doing.
“That’s what you saw after the game, he’s hugely popular. Very similar to Pape (Sarr), they’re just really nice natured young men who go with the flow but also have an inner determination to be the best they can be.”