London - Mauricio Pochettino faces a defining moment in his Tottenham reign as the in-demand Argentine tries to keep his bid for a first major prize alive against Borussia Dortmund in the Champions League.
Pochettino has taken to defending his failure to win silverware in almost five years at Tottenham by insisting he values qualification for Europe's elite club competition more highly than success in the domestic cups.
But for all of Pochettino's protestations that reaching the Champions League is his primary goal, that claim rings a little hollow when they never make it to the business end of the tournament.
Tottenham have never been past the last 16 of either the Champions League or the Europa League since Pochettino arrived from Southampton in May 2014.
Now Bundesliga leaders Dortmund, who visit Wembley for the Champions League last-16 first leg on Wednesday, stand between Pochettino and his first European quarter-final in what could his last season with the north London club.
Pochettino, yet to win a trophy in his managerial career, has been strongly linked with a move to Manchester United at the end of the season.
If that mooted deal may now be less of a sure thing given Ole Gunnar Solskjaer's remarkable impact as interim boss at Old Trafford, there is little doubt Pochettino will still be a man in demand, with Real Madrid also believed to be interested in his services.
Derided as serial underachievers when they struggled to break into the Premier League's top four, Pochettino has made Tottenham into Champions League mainstays capable of ruffling the feathers of Europe's aristocracy.
"We feel so proud and with all the circumstances the team is doing fantastically, the performance of the squad is unbelievable," Pochettino said.
"We are showing great character and very good quality, fighting against big sides and being in a position that's very close to the top.
"We hope to keep going in the same direction, to fight for big things."
But for all their undoubted growth in the Pochettino era, there remains a nagging feeling of unfulfilled potential about Tottenham, who have won only three cups in the past 28 years.
Failure to land a big prize with the generation of Tottenham stars he has cultivated so astutely, including Harry Kane, Dele Alli, Christian Eriksen and Son Heung-min, would be considered a missed opportunity.
Tottenham have finished in the Premier League's top three for the past three seasons and they retain an outside chance of winning the title this campaign.
But their poor record in domestic cups under Pochettino is a significant blemish and Tottenham's European exploits have been equally confounding.
Pochettino's first season featured a tame Europa League last-32 defeat against Fiorentina and the following year they were outclassed by Dortmund in the last 16 of the same competition.
His maiden voyage in the Champions League was even more rocky as Tottenham failed to qualify from the group stage.
Finally hitting their stride last season, Spurs enjoyed a memorable 3-1 win over European champions Real Madrid in the group stage and they also drew in Madrid and twice beat Dortmund.
But as the pressure mounted Tottenham melted, blowing the lead in the last-16 second leg against Juventus as two second-half goals sent them crashing out.
Vexed by mounting criticism following recent exits from the FA and League Cups, Pochettino said chairman Daniel Levy told him his brief was to finish in the top four while the club build their long-delayed stadium.
Although Spurs look set for another top-four finish, it would still be a source of angst among Tottenham fans if Pochettino departs without lifting a single trophy.