Gasol, the MVP of the 2006 FIBA World Championship was included in new coach Sergio Scariolo's squad at an announcement ceremony in Madrid though he is not yet a nailed on certainty to play.
"We hope that Pau can confirm this week that he will be available to play," said Spanish Basketball Federation president Jose Luis Saez.
"There are some minor details yet to resolve."
"In the case of Pau, never had we considered that Pau would not come," Scariolo said.
"Pau is extremely important for the national team. We hope that he will communicate as soon as possible his availability."
Scariolo has also included DKV Joventut point guard Ricky Rubio and addressed the difficult month the 18-year-old has had with respect to his potential move to the NBA.
Rubio's representatives and family have been unsuccessful in their attempt to get DKV to lower the player's buyout clause, which could result in the player remaining in Spain for one or two more seasons.
The teenager who made his senior team debut last year at the Olympics was chosen fifth overall in the NBA Draft last Thursday by the Minnesota Timberwolves.
"What has happened to Ricky in recent weeks obviously would have distracted anyone," Scariolo said.
"We hope it will not last too long. But everyone tells me that if there is a person that can deal with this with calmness, it is Ricky.
"We hope that all will be resolved before we meet on July 30."
Pamesa Valencia's Victor Claver, the 20-year-old selected 22nd overall in last week's draft by the Portland Trail Blazers, was included in the squad.
Claver missed most of last season with a knee injury but returned for the end of the campaign and Scariolo said: "He has a lot of potential and he's ready."
Carlos Cabezas missed last year's Olympics but has returned to the national team under his former coach at Unicaja Malaga, Scariolo.
He likely benefitted by Jose Calderon's unavailability, with the Toronto Raptors guard forced to rest after an injury-plagued campaign in the NBA.
Rudy Fernandez, Jorge Garbajosa, Marc Gasol (Gasol's younger brother), Raul Lopez, Alex Mumbru, Juan Carlos Navarro, Felipe Reyes and Berni Rodriguez are all in the squad.
Saul Blanco of Fuenlabrada, Sergio Llull of Real Madrid and Guillem Rubio of Ricoh Manresa have been invited to work out with Spain during their preparations.
Another former player of Scariolo's at Unicaja, Fran Vazquez, did not make himself available for selection.
Vazquez had a strong campaign with Barcelona and helped them win the ACB title.
"Fran Vazquez has not given his availability for personal reasons," Scariolo said, before commenting on Jose Calderon.
"The Jose Calderon injury has made it more difficult for us to get a replacement. Jose is a player of high level. This year it hasn't been possible but I hope in the future both Fran and Jose will have a place in the national team."
Sergio Rodriguez, who has endured a couple of disappointing seasons in the NBA and recently found out he was leaving Portland to play for Sacramento, was left out of the squad for a second consecutive year.
"These have been four intense months since I took over," said Scariolo, who replaced Aito Garcia Reneses as coach.
Scariolo, who is also the coach of BC Khimki Moscow Region, said: "I have learned more about the Spanish national team. We have worked on trying to reach the list of players …
"There are many players that have not been included but that merit the national team. I think we have done our job with consciousness.
"In the last few days we have decided to define the number of 12 players that will take part in the EuroBasket.
"There are factors that could affect the team from here until then but the three players (Blanco, Llull and Rubio) included at the beginning would be considered.
"We hope that with these players we can begin on July 30 our work with enthusiasm and hard work."
Spain also announced their friendly schedule.
In Las Palmas on August 14, Spain will go up against Cuba.
They will then fly to Madrid for friendlies against Lithuania, Slovenia and Great Britain (August 19, 20 and 21).
In Zaragoza on August 26 and 27, the Spanish will face Israel and Poland before wrapping up their preparations with friendly games against Iran and Lithuania in Vilnius.
They will then travel to Poland for the EuroBasket and play in Group C in Warsaw against Serbia, Slovenia and Great Britain.
Spain squad: Carlos Cabezas, Victor Claver, Rudy Fernandez, Jorge Garbajosa, Marc Gasol, Pau Gasol (still to be confirmed), Raul Lopez, Alex Mumbru, Juan Carlos Navarro, Felipe Reyes, Berni Rodriguez, Ricky Rubio. Invited to work out with team: Saul Blanco, Sergio Llull and Guillem Rubio
