Chiellini has announced his departure from club side Juventus and his international retirement at the end of this season, but the 37-year-old could continue to play in North America, according to several media reports.
The ‘Finalissima’ game at Wembley will be Chiellini’s 117th international appearance for the European champions.
“He made his choice and choices must be respected. I will speak with him to thank him, it’s normal for him to take another route,” Mancini told a press conference at the start of Italy’s training camp.
The defender won a bronze medal at the 2004 Summer Olympics with Italy before being called up for the senior team by Marcello Lippi in November that year against Finland.
Eighteen years later he is among a group of 45 players called up by Mancini in June. Italy face Copa America winners Argentina in London on Wednesday in the revived meeting of the champions of Europe and South America.
Italy will then play Germany twice, Hungary and England in the Nations League.
Mancini insisted that Chiellini would be the only retirement from the Azzurri, despite Italy missing out on a second consecutive World Cup.
“Some may play their last game of the season (against Argentina) and go home because we have to make choices, but no one is Giorgio’s age,” said Mancini.
“We have to start again, the supporters are still behind us despite what happened.”