De Haan started his managerial career in 1974 with VV Akkrum. After two years he combined this role with the youth team manager's position at SC Heerenveen. By 1978 he had become the manager for Drachtster Boys. He then moved to ACV in 1980, and to Steenwijk in 1983. In 1985 de Haan re-joined Heerenveen, this time as assistant coach. He would go on to spend 20 years with the club, the longest time a coach worked for a Dutch professional football club. De Haan was made head coach in 1992, and in 1993 led the club back to the Eredivisie. The finished in second place in the Eredivisie with Heerenveen in 2000, thus qualifying for the UEFA Champions League for the first time in the club's history.
De Haan had announced that he would retire from football at the end of the 2008–09 season, when his contract with the KNVB expired. Instead he returned to work as a senior advisor at SC Heerenveen, before being appointed head coach at South AfricanPremier Soccer League club Ajax Cape Town.