The 21-year-old was stretchered off last weekend with his left leg in a brace during his side's 1-1 draw with Bristol City in the Championship.
Poveda was forced from the field of play following a collision and was transferred straight to a local hospital for assessment alongside club doctors.
Rovers boss Tony Mowbray said initially that his medical staff believed the forward had suffered ankle ligament damage though after further evaluation it has now been revealed as a leg break, which will require surgery.
“The news isn’t particularly good. He’s broken his fibula, he’s got some ligament damage to the ankle,” Mowbray said of the Whites loanee.
“That’s a lot worse than we would have hoped because it did look relatively innocuous at the time. It’s not good news for him, or us.
“He’s not in the building, he went back with his parents after the game and we’ve been in touch with Leeds United and it looks like he’ll have an operation to plate it up and put the bone back.
“We’ll await what Leeds want to do with him, he’s their player but it will be a considerable amount of time to recover.
“We feel for him. He had made his breakthrough, we were starting to see the very best of him because he’s such a talent, the way he can dribble, use both feet and keep the ball tight.
“He was just acclimatising to the demands of the Championship and the physicality levels. It’s a blow for us but ultimately a bigger blow for him.”
Poveda was sent across the Pennines to Ewood Park in the summer by Leeds head coach Marcelo Bielsa in a bid to gain more first team experience.
The attacker was just settling into life in Lancashire amid the demands of England's second tier, having impressed with a goal and an assist against Sheffield United ahead of the November international break.
Following his impact against the Blades in what was his best performance in a Rovers shirt, he was handed a fourth start of the campaign at Ashton Gate - bringing his total up to eight appearances for Blackburn.
He is, though, now set for a long rehabilitation process with Rovers in discussions with parent club Leeds over the best course of action for his long-term recovery.
Poveda is contracted at Elland Road until the summer of 2024, having joined from Manchester City for an undisclosed fee in January 2020.