Spain coach Vicente del Bosque omitted Torres from his last few squads but on Monday included the 29-year-old striker in a 26-man party.
The group will be reduced to 23 for next month's tournament in Brazil following this weekend's final round of La Liga matches.
Torres netted 22 goals in 64 appearances for Chelsea this season and was a regular scorer in the Blues' successful Europa League campaign, including netting the opening goal in the 2-1 final win over Benfica earlier this month.
Also earning a recall was midfielder Martinez, who produced an impressive performance in Bayern Munich's Champions League final victory over Borussia Dortmund on Saturday.
"When they haven't been called up it's because we didn't think it was best. Now we think the opposite, we think that they are in a good moment," Del Bosque said.
Manchester City midfielder Javi Garcia, Real Betis midfielder Benat Etxebarria and Valencia striker Roberto Soldado are also in the provisional group, along with captain Iker Casillas, who has not played for Real Madrid since January.
Regarding the decision to name goalkeeper Casillas in his squad even though the veteran has not played competitively for almost five months due in part to a hand injury and also falling out of favour with Madrid coach Jose Mourinho, Del Bosque said: "We're certain he's in good form. We spoke in France and since then I haven't spoken to him, but I'm sure he is fine. He's one of us."
There is no place for Sevilla striker Alvaro Negredo or Athletic Bilbao forward Fernando Llorente, however.
Del Bosque admitted: "It's almost impossible to have every player who merited a place. (Cesc) Fabregas, (David) Villa, Torres and Soldado are our four strikers. You could just as easily ask why we didn't include (Imanol) Agirretxe, Iago Aspas, Michu...
"We can't bring in everybody. We've deemed it fit to call up Soldado because he's had a great season.
"We've called up those players who are going to help us have the best tournament."
He added: "It's impossible to please everyone. Some will say why are players like Xavi going who are tired.
"They all want to be here and are looking forward to it. No-one has said they don't want to be in the Confederations Cup."
Spain have been drawn in Group B of the Confederations Cup, with their first game coming against Uruguay in Recife on June 16.
Looking ahead to the tournament, Del Bosque said: "Not only are there four world champions but there are countries who are Olympic champions like Mexico and African champions like Nigeria.
"Japan are one of the countries who have made great progress and any of the teams could be uncomfortable opponents.
"We will try to be at the level we need to be."
Four days later they play Tahiti in Rio de Janeiro before taking on Nigeria in Fortaleza on June 23.
Prior to the tournament the world and European champions have friendlies against Haiti and the Republic of Ireland in the United States.
Spain squad: Casillas (Real Madrid), Reina (Liverpool), Valdes (Barcelona); Alba (Barcelona), Albiol (Real Madrid), Arbeloa (Real Madrid), Azpilicueta (Chelsea), Monreal (Arsenal), Pique (Barcelona), Ramos (Real Madrid); Alonso (Real Madrid), Benat (Real Betis), Busquets (Barcelona), Cazorla (Arsenal), Fabregas (Barcelona), Garcia (Manchester City), Iniesta (Barcelona), Martinez (Bayern Munich), Mata (Chelsea), Navas (Sevilla), Pedro (Barcelona), Silva (Manchester City) Xavi (Barcelona); Torres (Chelsea), Soldado (Valencia), Villa (Barcelona).