Federico Bernardeschi has pulled out of the Italy squad, having failed to recover from the muscular injury which has kept him sidelined in recent weeks.
Bernardeschi has missed Juventus' last two Serie A matches and their most recent Champions League fixture against Manchester United with an adductor problem.
He is nearing a return to fitness, having been named on the bench against AC Milan on Sunday, and Roberto Mancini chose to include Bernardeschi in his 27-man squad for matches against Portugal and the United States in the hope that he would be fit to play.
However, Bernardeschi has now been dismissed from the squad to continue his rehabilitation process back in Turin.
"Federico Bernardeschi has left the training camp at Coverciano," the FIGC confirmed in a statement.
"The Juventus player will miss the challenges with Portugal and the United States because of an adductor injury and in the next few hours he will return to his club to undergo the necessary treatment."
Bernardeschi now has ten days to recover before Juventus return to Serie A action against SPAL on November 24.
He will miss Italy's final UEFA Nations League match against Portugal at the San Siro on Saturday. Gli Azzurri must win to qualify for the finals of the competition next June.
Mancini's team also face the United States in a friendly in Genk three days later.
Bernardeschi has been capped 16 times by Italy, scoring just his second international goal in last month's draw against Ukraine.