PORTO, Portugal — Another attack had broken down, another minute had passed, and by now there was just a hint of panic in Kyle Walker's eyes. The Champions League title was slipping away. And so he did what he has been conditioned to do these past five years. He turned to the place that always gives him the answers. As Chelsea dallied over taking a goal kick, hoping to see a few more precious seconds ebb away as it closed out its victory, Walker and Manchester City's coach, Pep Guardiola, held an impromptu summit on the touchline. It was not hard to work out the dynamic. Walker wanted to know what to do. What had Guardiola seen? Where was the breach in the line? How did they rescue this? Guardiola responded with a torrent of instructions, as he always does. He is never short of ideas. Ordinarily, he passes them on to one or other of his fullbacks — the closest players to him — and they diffuse them through the rest of the team. This time, though, was different. Walker could see Guardiola's lips moving. He could hear the words coming out, just about, above the din of Chelsea's jubilant fans. But there was a look of blank incomprehension on his face, as if Guardiola had accidentally addressed him in Catalan or issued his instructions as a rap. Walker furrowed his brow and stared, hard, at his coach, in a vain attempt to make it all make sense. Whether what Guardiola said got through, whether it was put into practice or not, a couple of moments later Walker was back at the touchline, this time with the ball in his hands. He took a couple of steps, and then launched it long, deep into the penalty area. A beat later, the same thing played out. Manchester City, that byword for sophistication and planning and command under Guardiola, the outstanding strategist of his generation, the sport's great modern mastermind, had resorted to soccer's final roll of the dice, its last resort for the damned: the long throw-in. In the biggest game in the club's history, in his own long-awaited return to the Champions League final, the system that Guardiola has so obsessively, so painstakingly coded into his players' double helixes for half a decade had not just failed. It had broken down completely. There is a reason that, in times of trouble, Manchester City's players seek the counsel of the bench.