The 42-year-old star has revealed he will be starring in the upcoming DC Comics movie but he is yet to decide whether to play the titular character or his enemy Black Adam, reported Contactmusic.
"I am putting my heart and soul and my bones into this role," Johnson said.
Both characters have magical powers with orphaned boy Shazam possessing the ability to morph into an adult superhero simply by saying his own name.
Black Adam is a warrior who clashes with the titular hero during his quest for world power.
"We just had a big meeting with Warner Bros CEO regarding @DCComics 2014 we will partner up and create the cool bad assery. RockTalk (sic)," he had tweeted.
The star has been busy of late after filming action movie 'Hercules', in which he portrayed the titular leader.