"I haven't lost confidence in him," Brailsford told Cycling Weekly. "You have to look at the bigger picture, not just the performances over the last months."
The Tasmanian rode side-by-side with Froome in last year's campaign. Behind his captain, he placed second in the Critérium International, eighth in the Tour de Romandie and second in the Critérium du Dauphiné. On his own, he won Paris-Nice and placed second in País Vasco.
Sky gave him the green light over the winter to lead its Giro d'Italia squad but things fell apart this spring due to stomach problems. Porte fell sick during the Tirreno-Adriatico stage race and abandoned. He had to pull out of the Volta a Catalunya too.
Because of his problems, Sky had to reshuffle its Giro team and Porte's programme. Instead of focusing on the Giro d'Italia, they wanted him to get back to his best and lead Froome to a second Tour de France win.
"Because after Tirreno, he never quite got back on top of things. We said, 'You need a proper break'," added Brailsford. "He's come back, building up again and doing well."
Porte sat shotgun behind Froome up the Critérium du Dauphiné's first mountain finish on Monday while Geraint Thomas and Mikel Nieve led the charge. Spain's Nieve left Froome with around five kilometres to race up the mountain, where Froome decided to test his rivals.
Porte drifted back from the main group with Spanish team-mate David López around 8.1 kilometres remaining and closed the stage 10-27 minutes behind Froome.
"You need to wait until the end of the week to see where we are at instead of after every single hour and every single race," Brailsford said. "[That finish] was not a true reflection of where he's at."
Brailsford faith in the Australian 29-year-old runs so deep that he said that next year he could offer the leadership role again.
"Oh yeah, I believe in Riche Porte 100%. He's a fantastic climber, he gets time trialling right. With the right parcours and the right race, then I think he can win a Grand Tour,” explained Brailsford.
"He's very close. Once he gets [his rhythm] back he's definitely a force to reckon with."
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