The Germany international has been out of action since September with a knee injury but is now poised to make his comeback.
The Germany international joined the Viola from Bayern Munich last July for a reported 20 million euros but has not featured for the Italian outfit since September because a knee injury.
However, Montella said after Tuesday's Coppa Italia semifinal first-leg defeat at Udinese that Gomez is now set to make his comeback.
"The German is coming off four months of inactivity but he will return to training with the team from tomorrow [Wednesday]," the former Italy international told Rai Sport. "But his inclusion will be gradual."
Fiorentina succumbed to a late Luis Muriel goal at the Stadio Friuli, with Juan Vargas having earlier canceled out Antonio Di Natale's opener.
However, Montella was pleased with his side's performance in Udine and is in a confident frame of mind ahead of next week's second leg.
"We left Muriel in too much space for the goal but, overall, I'm satisfied," Montella said. "The Colombian unlocked a game that seemed destined to finish in a draw. Congratulations to them for believing in themselves but we could have also won the game. The tie is still open, though. The return leg will decide everything."
Udinese boss Francesco Guidolin was also quick to acknowledge that the tie remains very much in the balance.
"Our dream goes on, even if everything remains open," he said. "It was an even game. I liked my Udinese, but I also loved Fiorentina. Along with Juventus and Roma, they are playing the best football in the league. I am very pleased with my boys, though. It will be tough in the second leg, but we can continue to dream."