If a week is a long time in politics, this month has been an eternity in Wigan Athletic’s corner of football history. From that magical day at Wembley to the exhaustion and despair of relegation three days later, to the joy of the victory parade at which 30,000 Wiganers sang for Roberto Martinez to stay.

Ten or so days ago, it appeared the Wigan legend was making demands for further investment in the club’s training facilities and youth development — today, the club has announced that compensation has been officially agreed and he will leave to fill the managerial vacancy at Everton.

Well-deserved tributes to Martinez will follow in due course. He was far more than an employee during his managerial stint at Wigan Athletic — he represented the club as a true ambassador, with passion and pride, always portraying the club in the best possible light. He was a source of pride for most of the club’s supporters, a rarity in football who possesses a real love story with the club and town. He delivered footballing memories we shall never forget, including the club’s greatest achievement FA Cup victory but also the highest quality football the club has ever seen during last season’s great escape. He is and will remain an icon.

But he is gone, officially — and his departure leaves the club in a state of uncertainty. If the blow of relegation has been cushioned for many of us by the knowledge that his tireless work behind the scenes has left the club in strong shape for the long-term, his departure brings with it a wave of fresh concerns.

The immediate concern is a mass exodus. The loss of certain players was inevitable following relegation. But having already lost seven players to the expiration of the their contracts, either full-time or loan, the club now faces the challenge of keeping players who would have stayed loyal to Martinez but may now be tempted to follow his lead and jump ship. How many of the youngsters, especially the Spanish-speakers, will stick around for Championship football if a British manager takes over under a new playing philosophy? How many players — Alcaraz, Maloney and Kone spring to mind — will Martinez try to take with him? How many of the coaching staff will stay?

The longer-term concern is a potential loss of continuity. After four years of successfully revolutionizing the way the club played football from the youth teams upward, the club now faces the possibility of a new manager with a different footballing philosophy. The hope is that Dave Whelan will take a page out of Swansea’s book and prioritize continuity, bringing in a manager with a similar continental philosophy and an emphasis on youth development. Ideally, but impractically, Martinez would act in an advisory role to Whelan in the appointment of his successor to ensure his vision is continued.

The good news is that most of the candidates linked with the Wigan vacancy are promising from a footballing perspective. Gus Poyet is a personal favourite given his style of football, cultural and linguistic understanding, familiarity with the Championship, and relative youth. Rene Meulensteen represents a gamble, as Jakarta Jack recently wrote, but ticks many of the correct boxes with a continental approach, track record working with youth, and big-club pedigree. Karl Robinson is lesser known. Steve McLaren is experienced and did wonderful work at FC Twente and Middlesbrough, but has some blotches on his managerial record as well. Only Owen Coyle’s name sticks out as an unpopular candidacy. And finally, the Daily Mail couldn’t help but report that Whelan is after Steve Bruce for a third stint in the Premier League, this morning. Unlikely.

A swift appointment must be a priority. There will be much rebuilding over the summer. Poyet, Meulensteen and McLaren do inspire hope in the transfer market, something that should prove vital in the immediate future. But it remains to be seen what sort of budget Martinez’s successor is forced to operate within. There is a lingering sense of unfinished business for Martinez given the challenges posed by relegation. The biggest question is what led to the breakdown in talks between Whelan and Martinez, between that Friday when the Spaniard had asked for assurances about investments in the club, and the Monday when Whelan suggested he would be leaving. Did the manager ask the chairman for assurances about keeping certain players? About bringing new players in? Or strictly about investment in facilities and development?

The next few weeks promise to be unpleasant ones for the Wigan faithful. The ecstasy of the FA Cup win has been blunted by relegation and the slow and painful dismantling of the team that achieved it. The list of those to have left the club includes Antolin Alcaraz, Franco Di Santo, Maynor Figueroa, Ronnie Stam, Joel Robles, Angelo Henriquez, Paul Scharner, and now, most damningly, the captain of the ship, Roberto Martinez. Presumably his coaching staff will follow. Whelan’s swift action will be crucial. His managerial appointments in the past have largely been inspired, but this may be the greatest test yet.

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