Erwin is the son of Dutch international footballer Martin Koeman, and, alongside his younger brother Ronald, who is the Manager at Everton, has also represented the Netherlands.

All three Koemans played for Groningen at some time during their careers.

Erwin Koeman's son, Len, is also a footballer and currently plays for the Helmond Sport youth team.

Koeman played with Groningen, Mechelen, where he won the Belgian League in 1989 and 1988 Cup Winners' Cup during the team's heyday and PSV, where they became league champions in 1990–91 and 1991–92.

Koeman was a midfielder for the Netherlands that won the Euro 88 and featured in the 1990 World Cup.

In total, Koeman was capped 31 times, scoring twice between 1983 and 1994.

Koeman finished his playing career with Groningen in 1998 and became youth coach at PSV.

In October 2001, he was promoted to assistant manager under Eric Gerets, and for the 2004–05 season became manager in RKC Waalwijk.

He managed RKC for one season before moving to Feyenoord. In March 2006, he extended his contract to the summer 2009.

However, on 3 May 2007, Koeman announced his immediate resignation due to motivational problems, after a troublesome season, where Feyenoord eventually finished seventh.

Starting on 1 May 2008, Koeman became the coach of the Hungary national football team.

He was removed from his post on 23 July 2010.

Before the 2011–12 season, he was appointed as the new manager of FC Utrecht.

However, on 18 October 2011 he quit the job citing bad working conditions and frustration after several key players had been sold.

On 16 June 2014, he was appointed as the assistant head coach of Southampton, where he worked alongside his brother, Ronald, for the first time.

On 17 June 2016, Everton announced he would join brother Ronald, as Assistant Manager.

Erwin's role with the club ended on 24th October 2017, after the dismissal of manager Ronald Koeman.

Good luck to Erwin from all at Love Everton Forum.