None of the starting XI against City were involved at the Stadio da Mata Real, with Nuno handing full debuts to five players, including Spurs’ three summer signings and teenagers Nile John and Dane Scarlett.
“Of course it impacts [the mood] a lot,” the Spurs manager said afterwards.
“Nobody likes to lose a game or not play good.
“The feel-good factor disappears. This is football. It is up and down but how you realise that this is the situation, they have to bounce back. This is what we are going to do.
“The good part of football is that it gives you the chance immediately, and we have a chance on Sunday.”
Lucas Silva ran behind Spurs’ back three to score the only goal towards the end of the first half after Harry Winks had lost possession in the midfield.
“Not good, not good,” Nuno said of the performance. “First half we lost too many passes – and the goal came from that. We were imbalanced. But not a good performance, honestly not a good performance.
“Of course, players [were] coming back,” he added.
“The decision was basically trying to give them minutes. We need players to get minutes in their legs and increase their levels of fitness.
“I would decide exactly the same [again] because the main question is to use the squad as we have a long way to go and we need all the players involved.”
Scarlett, 17, completed 90 minutes on his first senior start but was starved of service as Spurs failed to have a meaningful effort on goal.
Nuno admitted the teenager could have been sharper, but put blamed at the supporting cast for Scarlett’s frustrating evening.
“He’s very young, he has talent,” the Portuguese said.
“As a team we should have made more chances for him, we didn’t finish the actions, we didn’t make too many offensive situations for him to be able to be able to even shoot on goal. That’s our responsibility.
“For Dane, it was good.
“He has to be faster on his decisions and his movement. With tough centre-halves on his back, it’s difficult. So there’s things we have to improve and we’ll work on it. We honestly believe there’s a lot of potential there and we have to develop and improve it.”