Rossi's injury-plagued career received another blow in September, when the Italy striker was ruled out for up to five months after undergoing knee surgery in Colorado.
The 27-year-old, who has only played 22 Serie A games since moving to Fiorentina from Villarreal in 2013, complained of discomfort during pre-season prompting the Italian club to send him for keyhole surgery in the United States.
"The recovery process is on schedule. I have read and heard all sorts of things, but it is part of the world we live in," Pastorello told Radio Fiesole.
"That's why I haven't spoken to the media since late August, as more balance and responsibility is needed.
"Rossi will be back stronger than before. He faced this injury with the same tenacity and I get the sense he's in a better mood than the other times.
"We know the medical situation and are optimistic. I can clearly say the rumour Rossi's career is at risk is entirely false and without foundation."
