He was forced to retire in 1993 after suffering a serious injury during Fred Rutten's farewell match.

[2] After retiring as a player, De Koning then became a goalkeeping coach for his former club AZ, also serving briefly as joint caretaker in 1997, and later on moved into head management at Eerste Divisie, making his debut at such role with Limburgish club Fortuna Sittard.

De Koning then briefly served as interim coach of Dordrecht from March to July 2005[1] before being appointed at TOP Oss later that year until June 2010 when he was removed after he failed to save FC Oss from relegation to the newly established Topklasse level at the end of the 2009–10 season.

[3] From July 2010, De Koning was in charge of Eerste Divisie club AGOVV Apeldoorn.

[6] On 21 April 2012, it was confirmed that he would be in charge of Eerste Divisie club Volendam for the 2012–13 season, signing a two-year deal.