James Cameron is planning to film the two follow-ups back-to-back, with the first slated to arrive in December 2014.
"Whenever Jim says. If he called me up this afternoon I'd be there," Worthington told Digital Spy of Avatar 2 and 3.
Asked about Cameron's recent dive to the Pacific Ocean's Mariana Trench, the Wrath of the Titans star responded: "I thought he was going to get eaten by a megalodon. I seriously thought a big octopus was going to come out and [eat him].
"As Liam Neeson said, be more worried for the octopus, because Jim probably would have caught him and pulled him up for lunch."
Worthington's Wrath of the Titans, which sees him return to the role of demigod Perseus, opens in cinemas today (March 30).