Japan manager Hajime Moriyasu banked on a risky strategy in Sunday's 1-0 loss to Costa Rica that seemingly underestimated the Central Americans and hurt his own team's hopes of progressing to the World Cup round of 16.
By rotating his squad to keep players fresh for later games, Moriyasu overlooked both Japan's opponent and the incredible opportunity presented by the Samurai Blue's historic 2-1 win over Germany earlier in the tournament.
Had he sent a full-strength team onto the Ahmad Bin Ali Stadium pitch to face a side reeling from their 7-0 drubbing by Spain, Moriyasu would already be planning for the knockout rounds.
With Spain and Germany drawing 1-1 later on Sunday, Japan remained second in Group E on three points, one behind Spain and well ahead of Costa Rica on goal difference. Germany are last on one point, but in strong contention for a top-two finish with a game against Costa Rica remaining.
Japan's fate is in the players' hands, with a win over the 2010 champions on Thursday enough for them to advance. A draw could also do it, but only if Germany do not beat Costa Rica by a margin big enough to overtake Japan on goal difference or, if that does not separate them, total goals. If Japan gets a point, Costa Rica can advance with a win.
Speaking at Sunday's post-match press conference, Moriyasu said he had no regrets about how he approached the Costa Rica game, nor how he prepared and instructed his team to play. Despite their dire showing, he insisted that everything had been going to plan -- until it was not.
His players backed the manager in the wake of the shock defeat.
"We made changes from the first half and tried to have a focal point on the side, but it didn't work out well," said captain Maya Yoshida, in something of an understatement.
Costa Rica had the fewest touches in the opposition box of any winning team since the 1966 World Cup, when the data was first collected, according to sports analytics firm Opta.
While Japan dominated territory, they ended up with nothing to show for it.
"We wanted that opening goal and our attacks were effective, but we made things tough for ourselves with mistakes in our link-up play," Sporting Lisbon midfielder Hidemasa Morita said.
The manager must take much of the responsibility for that lack of cohesion, which stemmed from his decision to make over the lineup.
The addition of Ritsu Doan, Morita and Yuki Soma to the midfield behind Ayase Ueda yielded poor results.
Ueda was particularly ineffective in the No. 9 role. He was unable to hold the ball in a forward position and when he did gain control, his passing was off. In his 45 minutes on the pitch, he did not attempt a shot.
Moriyasu recognized it was not working for Ueda and benched the 24-year-old Cercle Brugge player for the second half, putting Takuma Asano in his place.
The change brought an immediate spark, with Asano involved in two shots on target within minutes of him entering the game, the second off his own head. Japan had two total shots before that point, with neither on target.
Yoshida said the team's attack became stale against a Costa Rican defense prepared to spend long stretches with almost every player behind the ball.
"We couldn't break down their block and our playing tempo became really flat," he said.
Against Germany, Brighton & Hove Albion winger Kaoru Mitoma was part of the substitute contingent that swung the game in Japan's favor.
Moriyasu chose to keep him as a bench sparkplug against Costa Rica and it almost paid off in the last minutes, when he made one of his trademark dribble forays and found Daichi Kamada, who was denied an equalizer by Paris Saint-Germain stopper Keylor Navas.
Mitoma was blunt in his assessment of his team's shortcomings.
"We made many mistakes and conceded when we shouldn't have," he said.
"There were individual mistakes and we were losing out when vying for the ball in the first half too, some details (need fixing)."
With his 83rd-minute equalizer against Spain, German substitute striker Niclas Fuellkrug kept his team in the tournament while also complicating Japan's path. For the Samurai Blue, the equation should nevertheless be straightforward -- beat Spain to extend their stay in Qatar.