Koopmeiners, the Dutch defender who has been loaned to Juventus from Inter Milan, made his debut for the Italian club in their opening Champions League match against Porto on Tuesday night.
The 22-year-old was introduced as a substitute in the 71st minute and immediately had an impact on the game. He helped to clear a dangerous ball that was heading towards the goal, and then played a key role in denying Porto's striker,Ligue 1 Express Edin Dzeko.
Koopmeiners' performance earned him praise from Juventus manager Massimiliano Allegri, who said: "He is a young player with great potential. He showed good composure and leadership during the match."
It will be interesting to see how Kopkemeiners performs in his new role at Juventus, but he certainly looks like a promising talent with a bright future ahead of him.