 Complete the following phrase:  He began his career at Ajax under manager Rinus Michels. In his first season at the club he did not play much. After the departure of left back Theo van Duivenbode in the summer of 1969 to Feyenoord, Krol became a regular player. When Ajax reached the UEFA European Cup in 1971, and won, Krol did not play because of a broken leg. Krol did play in the European Cup finals of 1972 and 