Former Yamaha team manager Brivio followed Rossi to Ducati this year to continue working with the seven-time MotoGP champion. Writing on his Twitter feed today, Brivio said there was no truth in suggestions that Rossi was set to stop racing.
"Many are asking about Vale stopping races," Brivio wrote.
"This is absolutely not true and I'm sorry even that I have to explain it..."
Rossi and Tech 3 Yamaha's Colin Edwards struck Simoncelli's Gresini Honda in yesterday's accident on lap two of the Malaysian Grand Prix.
Simoncelli suffered severe head, neck and chest injuries in the crash, which happened as he slid into his rivals' path during a low-side fall, and was pronounced dead at the circuit's medical centre less than an hour later.
Yesterday Rossi paid his own tribute to Simoncelli on his Twitter account.
"Sic was like a younger brother to me," Rossi wrote. "He was as tough on the track as he was sweet in life.
"I still can't believe it, I'll miss him hugely."