VIDEO: Mark Ruffalo Recalls Robert Downey Jr. Convincing Him to Play Hulk in 'The Avengers'

In a recent interview on The Tonight Show Starring Jimmy Fallon, Mark Ruffalo revealed that fans have another Marvel star to thank for getting him involved in the franchise.

While speaking to Fallon virtually, Ruffalo explained that he was nervous to play Bruce Banner after Edward Norton had already portrayed the character in the 2008 film The Incredible Hulk. "I was scared," he told the late-night host. "I didn't know what I could add to what I already thought had been done so well before me." He also noted that up until playing Banner in The Avengers, he had mostly been working on indie films and didn't know how he felt about being in such a big blockbuster. "So I was like, 'I don't know if I'm the right person for this.' And [The Avengers director] Joss Whedon's like, yeah, you are the right person,'" Ruffalo recalled.

However, the three-time Academy Award nominee credits his co-star Robert Downey Jr. with ultimately persuading him to join the cast. "I got a call from Downey, it must've made it to him that I was hemming and hawing, and he just simply said, 'Ruffalo, let's go. We got this.' In true Iron Man fashion," he recalled. "And then after that, I was like, 'I guess I have to do it.'" You can check out the full interview below.

Ruffalo continued to discuss how Marvel's secrecy about their projects made him once again question if he wanted to come on board as Bruce Banner. "I wanted to read a script, and they don't give you scripts. I made a promise when I was a young actor that I would never do another movie without reading a script beforehand, because it's a recipe for disaster, and then you get stuck in something — our only power as young actors are our ability to say 'no' sometimes," he explained. "And so I was like, 'I need to read something,' and the studio was like, 'We're sorry, we don't give anything out.'"

At the end of the day, Whedon came to the rescue by giving the actor 20 pages of what he had written so far for Bruce Banner's character. His introduction to the character was a scene that I've always loved. "I read that first scene of when Scarlett [Johansson], when Black Widow finds Banner in India, and I was like, 'Okay, I love this. It was different, you know," Ruffalo said of the script. "I was like, 'Oh, okay ... It's humorous and it's kind of playful and I think I could do something with it.'"

Thank goodness Whedon and Downey came together to convince Ruffalo that he needed to play The Hulk. It's hard to imagine anyone else playing him! The actor has actually talked about possibly returning to the MCU as Banner in the upcoming Disney+ series She-Hulk, which you can read about here.