Ricki Herbert has resigned from the Wellington Phoenix, ending the longest tenure by any A-League soccer coach.The Phoenix announced it had accepted Herbert's resignation five games from the end of a disappointing season and offered the 51-year-old All Whites mentor an advisory role at the club.He has accepted the position of technical football advisor to the board, with assistant coach Chris Greenacre to take over as coach for the remainder of the season.Herbert was appointed coach by owner Terry Serepisos when the Phoenix were formed in 2007, and his 154 games in charge make him the league's longest-serving coach.However, their slide to last place in his sixth season in charge had taken its toll."The results this year have not been what anyone would have wanted and I felt that it was time for someone else to take a fresh look at things at the club," Herbert said in a statement."The coaching staff and players have all put in a huge effort this year but we haven't got the results we wanted.""I've had a long and very successful tenure at the club and will always be proud of what I have achieved."Phoenix chairman Rob Morrison was pleased Herbert had accepted the new role as the club wanted to retain his knowledge and expertise."Ricki has an unparalleled record in the A-League. Without his contribution the Phoenix could not have had the success it has had," Morrison said.Former Phoenix striker Greenacre will take charge for Wednesday's home game against the Newcastle Jets, hoping to revive the fortunes of a team who have managed just five points from a possible 27 in 2013 and sit last on the table with 21 points. They sit six points outside a top-six playoff berth, having won just five of 22 games.Dwindling crowds have marked recent home games while they were embarrassed across the Tasman in losses to Sydney FC (7-1) and the Central Coast Mariners (5-0).It is a significant fall after reaching the playoffs for each of the last three seasons - the only club to do so.This year's Phoenix playing roster was touted as the strongest in their history, prompting captain Andrew Durante to target a top-two finish a few rounds into their campaign.However, performance levels dropped away at the same time as club owners began demanding a more attractive playing style.These changes were supported - at least publicly - by Herbert, whose critics have long accused him of a conservative, inflexible style.His detractors also believe Herbert has wielded too much power as both national coach and mentor for the most prominent club team in New Zealand.Herbert guided the Phoenix to last and sixth in their first two seasons of an eight-team competition before making the playoffs in their best season of 2009-10.They drew record home crowds in excess of 30,000 in the playoffs before losing the preliminary final against Sydney FC.In a 10-year career as a reliable defender for New Zealand, Herbert played 61 games and scored key goals on the road to qualifying for the 1982 World Cup.Appointed All Whites coach in 2005, he rose to fame at the 2010 World Cup when New Zealand drew all three of their group games in South Africa.His next coaching assignment is preparing the All Whites for an important World Cup qualifying match against New Caledonia in Dunedin on March 22.