Mark Ruffalo joined Jimmy Fallon for a virtual chat on Friday’s “Tonight Show”, and revealed how Robert Downey Jr. convinced him to take on the role of the Hulk and join the Marvel Cinematic Universe in “The Avengers”. “I was scared,” he said of stepping into the role, which had previously been played by Edward Norton in 2008’s “The Incredible Hulk”, Eric Bana in 2003’s “Hulk” and Lou Ferrigno in the 1970s TV series. “I didn’t know what I could add to what I already thought had been done so well before me,” Ruffalo told Fallon. “And I had only been doing indie movies up to that point so I was like I don’t know if I am the right person for this role.” RELATED: Mark Ruffalo Reveals His Thoughts On A ‘Hulk’ Standalone Movie: ‘It Could Be