Ever since Mark Ruffalo was cast as the Hulk for the first "Avengers" film, speculation has lingered as to when -- if ever -- Marvel Studios may give a solo Hulk film another try. For a long time, it's looked pretty unlikely -- in March 2013, Ruffalo flatly said it wasn't in the works -- although the actor has continued to hold out hope.

In an interview with Digital Spy promoting upcoming musical "Begin Again," Ruffalo indicated that, from his vantage point, Marvel is more open to a new "Hulk" movie than they've been in the past -- while making clear that doesn't mean it's anywhere close to happening.

"I think they are, for the first time, sort of entertaining the idea of it," Ruffalo said. "When we did 'Avengers '1 it was basically, 'no.' Now I think there is some consideration for it, but still nothing definitive -- not even a skeletal version of what it would be."

"I look forward to going down that road if we can crack the nut," Ruffalo continued. "I think the Banner/Hulk storyline is obviously not an easy nut to crack."

The next time Ruffalo will be seen as the Hulk on screen will be in 2015's highly anticipated sequel, "Avengers: Age of Ultron." In the same interview, Ruffalo said that fans of the Tumblr-adored pairing of his Bruce Banner and Robert Downey Jr.'s Tony Stark will be pleased with the film.

"There's some very cool Science Bros stuff," Ruffalo said.