Trafford was in celebratory mood earlier in the week when he collected the PFA’s Championship player of the year award at the Opera House in Manchester city centre, reward for his performances in the second tier for Burnley.
The 22-year-old kept 29 clean sheets in the league last season for the Clarets, and after joining City he was quickly on song, as Guardiola pointed out, in the opening win at Wolves.
But this was a different story, a difficult first showing in a City shirt at Etihad Stadium.
Trafford came through the City ranks and rejoined the club for £27m from Burnley this summer having not made a senior appearance in his first spell.
He will have been dreaming of playing Premier League football for City at the Etihad, but it turned into an uncomfortable afternoon, Trafford slipping away from centre stage at the final whistle with songs from joyful Spurs fans ringing in his ears.
Guardiola has turned to youth in his rebuild.
Saturday’s team, with an average age of 24 years and 326 days, was the youngest starting XI named by the Spaniard in the Premier League and they have plenty to learn.
Tottenham’s Richarlison pressed relentlessly all game and forced Trafford into conceding a corner, while the keeper was lucky not to be dismissed for a collision on the edge of the box with Spurs winger Mohammed Kudus.
And at 1-0 behind, with the crowd beginning to get anxious, those shaky moments then turned into a calamity as Trafford played a loose pass inside the area to Ruben Dias, who failed to control, and Joao Palhinha eventually smashed in.
City failed to recover, slipping to defeat in their first home game of the campaign.
“City were well beaten today,” former Premier League striker Chris Sutton said on BBC Radio 5 Live. “I’ve got to say I’m not sure about the goalkeeper situation.
“Is James Trafford really top drawer? If it’s a choice between Trafford and Ederson, I’m going with Ederson.
“It was poor for the goal, a weak pass into Dias, not even passing on to the right side, and that absolutely killed them with Spurs going in 2-0 at half-time.”