 Complete the following phrase:  On 21 September 2016, De Ligt made his debut for Ajaxs senior team in a cup game against Willem II. He scored from a corner after 25 minutes, making him the second-youngest goalscorer ever behind Clarence Seedorf. On 24 May, he became the youngest player ever 17 years and 285 days old to play in a major European final when he started against Manchester United in the 