3. This defender played for various Dutch teams, including Heerenveen and Groningen. Both his sons, Ronald and Erwin, represented the Netherlands at an international level and, in Ronald's case, went into management. Who is this footballing father?
From Quiz Fathers' Day
Answer:
Martin Koeman
Despite being regularly called up to represent his country, Martin Koeman was only capped once for the Netherlands, against Austria. As well as playing for Heerenveen, he briefly managed them in 1987. He died in 2013.
Ronald Koeman was one of Barcelona's top scoring defenders, and was capped 78 times for the Netherlands, while Erwin had 31 caps. Both brothers went into management after retiring; Erwin managed Utrecht, RKC Waalwijk and the Hungarian national team, while Ronald's managerial CV includes Ajax, Valencia, Feyenoord, Everton, Southampton and the Dutch national team (with Erwin as assistant manager in the last three cases). One of the stands in Groningen's Euroborg stadium is named the Koeman Stand after the three players. Martin Koeman's grandsons, Ronald Jr. and Len, are also footballers.