Pedri and Unai Simon were among a group of six Spain stars at Euro 2020 who received an Olympic Games call-up on Tuesday.
Spain Under-21 head coach Luis de la Fuente, who will take charge of the Olympic team in Tokyo, announced a 22-man list that must be trimmed to 18 for the tournament.
Teenage Barcelona midfielder Pedri has been one of the standout figures in Luis Enrique's Spain team at the European Championship, while Athletic Bilbao goalkeeper Simon got away with a huge mistake in the last-16 game against Croatia, when he conceded an own goal before Spain roared back to earn a 5-3 win.
He carelessly failed to deal with Pedri's back pass and the ball rolled into the net.
They were joined on De la Fuente's squad list by senior Spain colleagues Eric Garcia, Pau Torres, Dani Olmo and Mikel Oyarzabal.
As expected, there was no place for veteran Sergio Ramos, who wanted to represent Spain at both Euro 2020 and the Olympics this year but was called up for neither tournament.
Ramos, who is leaving Real Madrid after 16 years, endured an injury-plagued 2020-21 season.
Spain, who were gold medallists in men's football at the 1992 Barcelona Olympics, also included Real Madrid duo Dani Ceballos and Marco Asensio, Valencia's Carlos Soler, Sevilla's Bryan Gil and Mikel Merino of Real Sociedad in a strong line-up.
Monday's victory over Croatia at Euro 2020 has carried Spain through to a quarter-final against Switzerland, to be played in St Petersburg on Friday.
Should Spain go all the way to the final, they will contest the showpiece at Wembley on July 11.
The Olympic football competition begins before the Games is officially declared open, with Spain due to play Egypt at the Sapporo Dome in their opening Group C game on July 22, a day ahead of the opening ceremony.
De la Fuente said he had no doubts about selecting Simon, despite his error at the Euros.
"I know Unai Simon. I know of his strength and integrity," De la Fuente said. "Yesterday he had an exceptional reaction after a difficult moment."
Provisional Spain squad for Tokyo Olympics: Alvaro Fernandez (Huesca), Unai Simon (Athletic Bilbao)), Alex Domínguez (Las Palmas); Mingueza (Barcelona), Jesus Vallejo (Granada), Eric García (Barcelona), Pau Torres (Villarreal), Oscar Gil (Espanyol), Juan Miranda (Real Betis); Marc Cucurella (Getafe), Jon Moncayola (Osasuna), Martin Zubimendi (Real Sociedad), Dani Ceballos (Real Madrid), Mikel Merino (Real Sociedad), Carlos Soler (Valencia), Pedri (Barcelona); Bryan Gil (Sevilla), Marco Asensio (Real Madrid), Dani Olmo (RB Leipzig), Mikel Oyarzabal (Real Sociedad, Rafa Mir (Wolves), Javi Puado (Espanyol).