The forward pair have suffered knee injuries and Fiorentina lacked sharpness in attack as they drew 0-0 with Torino on Sunday.
Montella was happy with his side's work-rate, but acknowledged the need for a new forward in the January transfer window.
"I would focus on the hard work and consistency of the team today," Montella told Sky Sports Italia.
"We tried to win the game, but we didn't manage it. We kept a clean sheet against an organised side like Torino, which is already something positive.
"It is evident we have been unlucky with Rossi's injury, as there aren't many great strikers on the market.
"Who is the perfect forward for our style of football? The one who guarantees goals."
Fiorentina director Daniele Prade admitted that the Serie A outfit are looking at out-of-favour Manchester United midfielder Anderson.
"We like Anderson, we're following him but like many other players," he said.
"We always pay attention to the transfer market, ready to strengthen our roster."
