The AC Milan senior advisor spoke to Sportmediaset after Alajbegovic's strike in Bosnia's 3-1 win over Qatar helped his country reach the last 32 — a result that has intensified interest from several clubs, including AS Roma and Atalanta in Serie A.
"The finish was beautiful, yes. The technique was perfect, yes," Ibrahimovic said.
"But what struck me was the confidence before the goal. The way he called for the ball, the way he sensed the moment. Great players don't wait for chances. They create them.
"Everyone talks about the goal, but for me the goal is not the greatest thing."
He went on to single out Alajbegovic's composure at such a young age as the quality that separates him.
"The most surprising thing is his courage," Ibrahimovic said. "An 18-year-old at the World Cup, under pressure, with millions of people watching, playing as if he owns the stadium. That is rare.
"Many young players have talent. Talent is everywhere. But talent without personality is worthless. When I watched Kerim, I didn't see a young player hoping to have a good game. I saw a player who believed he was the best on the pitch."
Ibrahimovic closed with words that felt more like a coronation than a compliment.
"People will say this is the beginning of his career. Maybe. But if he maintains this mentality, this goal will be remembered as the moment football realised who Kerim Alajbegovic is. The World Cup is where stars are born. Today, a new one introduced himself."
Alajbegovic's goal against Qatar was a strike from around 25 yards that helped Bosnia to a 3-1 victory and secured their progression to the knockout stage. For Ibrahimovic, it was the moment before the goal — the belief and the body language — that revealed most about the young player's ceiling.