The Brit crashed out of the Tour de France, which he was defending, after fracturing his left wrist and right hand in multiple crashes.
Team Sky principal Brailsford was unwilling to guarantee the 29-year-old's place, but said he wanted Froome to race another Grand Tour before the 2015 Tour de France.
"It's a bit early to say on that one," he said.
"There is a certain amount of training that needs to be done and a level of fitness Chris needs to achieve before the Vuelta.
"I think it's important he gets a grand tour in his legs and, from my point of view, the 2015 Tour de France starts now and the Tour of Spain is part of our build-up to trying to win the Tour back next year."
Another rider who crashed out of the Tour, Alberto Contador (Tinkoff-Saxo), will miss the Vuelta – which starts on August 23.
Brailsford said Froome's crashes, which forced his withdrawal on stage five, had made him hungrier.
"Chris has been resting up and recovering over in America for the last few weeks, but he was watching the race and I know he was missing it," he said.
"This setback has made him very, very hungry, and more determined than ever to come back next year and fight for that yellow jersey again."
Team Sky could only manage a seventh-place finish in the team classification at the Tour, but Brailsford said it was far from a disaster.
"We won this race twice and that was fantastic," he said.
"When you win you have to win with dignity and when you lose you have to lose with dignity.
"We had the pleasure of winning this great race twice so chapeau [hats off] to all the riders who rode well, especially to [Vincenzo] Nibali and also the French who have done well this year.
"This year wasn't our year but we'll try again next year."