Quique Setien, the new man in charge of Barcelona, takes on his new, demanding job with a clear signpost about what mistakes he must not make. There are two big ghosts in the building: Liverpool’s astonishing comeback against Barca last season, and the miniature replica, conjured up in ten minutes by Atletico Madrid, last week. Barca were 3-0 up against Liverpool more than halfway through their Champions League final in May, and they ended up losing. They led 2-0 against Atletico at half-time of their Spanish Super Cup semi-final in Jeddah six days ago and conceded twice after the 81st minute to sink to a 3-2 defeat. Collapse had become too much of a habit, even for a head coach at the top of La Liga, as Ernesto Valverde was at the time of his sacking. But Valverde sensed long before the setback in Saudi Arabia that he would never enjoy the sort of long-term security of his two nemeses in those defining matches – Jurgen Klopp of Liverpool, and Diego Simeone of Atletico. Between them, that pair have been in the same job for more than 12 years. That makes them outliers. Klopp has recently signed a contract extension that would, if he sees it out, keep him at Anfield until 2024. That would be almost nine years after he arrived. Simeone has just entered his ninth year as Atletico boss, and although he had endured a testing time lately, the stability he has brought to a club that was once a byword for trigger-happy presidents has been exemplary. It is hard to imagine Atleti without him. Along with Liverpool and the current Manchester City, Atletico have the most distinct identity among the elite clubs of European football. Long-term faith in the manager is why. Liverpool will meet Atletico next month in the last 16 of the Champions League, and once either Klopp or Simeone have been eliminated, the European Cup will be landscape overpopulated with managers who have had only a brief time to establish patterns, and build relationships with their players. Guardiola, three and a half years into his stunning overhaul of City, and Atalanta’s Gian Piero Gasperini, another coach with brave dogmas about how the game should be played, are the only men in charge of last-16 clubs with more than two uninterrupted years behind them. Momentum in sport is fragile, but it can be cultivated, and a coach who knows his team intimately is best equipped to do that. Jose Mourinho, who has never stayed at a managerial post for longer that three seasons, gave an insight into the mechanics of building momentum at the weekend. His Tottenham Hotspur had just been defeated by Liverpool, the latest scalp on Klopp’s 38-match unbeaten run in the Premier League, and Mourinho cited a key difference between his team and Klopp’s. “Liverpool have been with this coach for about five years,” Mourinho pointed out, adding a few months to Klopp’s tenure, “so the players are totally adapted physically to the football that he wants to play. It is a very high intensity.” Mourinho’s Spurs would not match that intensity over 90 minutes, Mourinho calculated, because there remains a disconnect between a manager, Mourinho, who only took over eight weeks previously, and players still getting used to him. “When people talk about physical condition in football, the important thing is that physical condition is adapted. If we tried to play the [more ambitious, energetic] way we did in the last 15 minutes from the beginning [of the game], I think we would collapse, because the players are not used to playing in this style and they are not adapted.” By contrast, Liverpool and Klopp have achieved a harmony. Its result, Mourinho suggested, is a special sort of stamina. Valverde is entitled to feel that, with Barcelona top of La Liga, having finished 11 and 14 points above second-placed Atletico the past two seasons, he has been judged by almost impossible standards, and a very rigid set of ideas. With the exception of Guardiola’s treasured period as head coach at Camp Nou, from 2008 to 2012, and Johan Cruyff’s time in the late 1980s and early 1990s, the club’s sense of identity is something a coach inherits, has to live up to, rather than defines. Barcelona looked for that identity, and a form of continuity that could be bolted-on when they frantically sought for replacements for Valverde. They approached, in vain, Xavi, the former captain, and Ronald Koeman, the ex-Barcelona player of the Cruyff era, who both have a distinguished playing history with the club. Setien merely has a long history of declaring how much he admires the Barca as defined by Cruyff and Guardiola. He will soon discover that admiration does not guarantee extended respect for the office of head coach.