Trafford was caught playing out from the back, and Richarlison fed Joao Palhinha to score Tottenham's second with a deflected shot, as City suffered their first loss this season.
"We always have arms around the shoulders," Guardiola told reporters on Friday.
"What happened doesn't belong just to James in the second goal. He is a strong man and a huge personality. We are here to help them, no doubt about that."
However, the manager said he would decide on Saturday who would start in goal at Brighton, as he aims to guide City to their seventh league title during his tenure.
"After two games, I feel like we're going to have a good season. I know that people may not believe it, despite what happened in the last game and maybe on Sunday," the coach said.
Guardiola said left back Rayan Ait Nouri, who was withdrawn after suffering an ankle twist last weekend, is fit for Sunday's match.