GEOFF COOK admits he will be leaving Durham with a “heavy heart” after the club announced his spell as director of cricket was coming to an end as part of a staff restructure.

Cook, who returned to his native North-East in 1991 after a county cricket career with Northamptonshire, has been one of the most influential figures in Durham’s rise from the minor county ranks to the very pinnacle of the professional game.

He was one of the driving forces behind Durham’s admission to the first-class ranks in 1992, and was the county’s first County Championship captain.

He ran the county’s youth academy following his retirement from the playing ranks, and was instrumental in helping develop a crop of players including Paul Collingwood and Steve Harmison that went on to star at national and international level.

The Teessider’s successes with Durham’s academy led to him replacing Martyn Moxon as head coach in March 2007, and within six months, he was guiding his side to their first major piece of silverware as they claimed the Friends Provident Trophy at Lord’s.

That victory started a remarkable run of success that saw Durham claim back-to-back County Championship victories in 2008 and 2009.

Poor health forced Cook to take some time off during the 2013 season, but he returned to work to join in with Durham’s Championship celebrations at the end of the summer and was appointed as director of cricket, with Jon Lewis taking over a head coach.

Now 66, he has worked in that role for the last five years, nurturing the likes of Ben Stokes, Mark Wood, Scott Borthwick and Mark Stoneman as they completed their progression to the England ranks and overseeing a series of successes as second XI and youth level.

“It comes with a heavy heart that I am leaving my role as director of cricket at Durham County Cricket Club, but I’m immensely proud of the work we have achieved during my 27-year stay,” said Cook. “It’s been a privilege to work at Durham for so long and the memories will be with me forever.

“From establishing ourselves as a first-class county to our back-to-back title wins in 2007 and 2008, and the Championship triumph in 2013 were, alongside many more, the highlights of my career.

“There are too many people to thank but I would like to show gratitude to all the players, staff, members and supporters I have worked with and of course my family and friends.

“Durham County Cricket Club is a great club and will continue to improve, I’d like to wish them the best of luck going forward.”

The announcement of Cook’s departure comes less than a week after Collingwood revealed his plans to retire at the end of the season, and the duo’s exit represents something of a changing of the guard at Emirates Riverside.

Durham have struggled to recover from the penalties imposed by the ECB after the county experienced serious financial difficulties, and have failed to win promotion from the Second Division of the County Championship this season.

The county’s new chief executive, Tim Bostock, is understood to have overseen a review of the club’s cricketing structure, and Cook’s departure forms part of a wide-ranging overhaul.

Marcus North is an early favourite to replace Cook as director of cricket, with the former Durham batsman, who played in 21 Tests for Australia, currently acting as chief executive of South Northumberland CC as well as fulfilling a number of media roles.

Lewis’ position as head coach is not understood to be under threat, but Cook’s departure will leave a huge gap to be filled.

“Geoff is a true legend of the club and his instrumental work has had an immeasurable impact on the success of Durham County Cricket Club,” said Durham chairman Sir Ian Botham.

“His efforts in establishing Durham as a first-class county and turning the team from newcomers to a title-winning force will never be forgotten alongside his superb coaching achievements. I would like to wish him the very best for the future.”