The rookie Tech 3 Yamaha rider fell at a high-speed downshill chicane and got his left hand caught underneath the bike as he slid into the gravel, leaving Smith with a gruesome wound on his left little finger.
His injuries will need to be re-examined before the race in Barcelona and a planned skin graft has had to be cancelled, but the Briton will be fit to race in Spain.
Smith, who bravely finished ninth in Sunday's race at Mugello, told motogp.com: "The good news is I will be fit to ride again at the next round at Barcelona.
"The bad news is I have a cracked bone in the scaphoid of my left wrist and the little finger on my left hand will be permanently bent.
"The doctors were unable to carry out the planned skin graft operation because the skin was so badly damaged around the little finger, but they are confident it will heal - as will the crack in the wrist."