Chris Pratt: 'Avengers: Infinity War' Will Be "The Biggest Movie Of All Time"

Guardians of the Galaxy and Avengers: Infinity War star Chris Pratt says the upcoming Marvel [...]

Guardians of the Galaxy and Avengers: Infinity War star Chris Pratt says the upcoming Marvel blockbuster will be the "biggest movie of all time."

Pratt took to his Instagram page to share his Empire Magazine cover that hails Infinity War as "a blockbuster event a decade and 18 films in the making."

The cover — one of six featuring the film's massive cast — sees Pratt's Star-Lord front and center, flanked by Gamora (Zoe Saldana), Hulk (Mark Ruffalo), Spider-Man (Tom Holland) and Falcon (Anthony Mackie).

"Empire is right! So grateful to be part of #Marvel's 10 year cinematic reign," Pratt wrote.

"[Guardians of the Galaxy and Guardians of the Galaxy Vol. 2 writer-director] James Gunn called me last night floored after having seen the movie. I expected no less. I cant wait until I'm parked in front of the screen popcorn in hand. I'm so excited for the world to see what we've been cooking up. Im honored to be a part of what will be the biggest movie of all time."

Pratt opened up to Empire about his Marvel Cinematic Universe welcoming from franchise star Robert Downey Jr., saying the Iron Man actor was the first to reach out when Pratt first claimed the Star-Lord role ahead of Guardians of the Galaxy's blockbuster release in 2014.

The star, who also headlines Universal's mega-hit Jurassic World franchise, said Downey inspired him to pay it forward with Marvel colleagues and franchise newcomers Tom Holland and Chadwick Boseman, who boarded the cinematic universe in 2016 as Spider-Man and Black Panther.

"I'm not saying that I'm senior to them, other than I got that experience of opening a movie with Marvel and being along for the ride," Pratt said. "Now I just really feel compelled to offer them, even if it's a fraction of what Downey was able to offer me, and just say, 'Anything you need, you let me know.'"

The Avengers threequel comes as Marvel Studios' latest, Black Panther, spent five consecutive weeks dominating the global box office — making it only the 14th film in history to cross the $1.2 billion dollar mark worldwide.

Infinity War broke records March 16 to become the best-selling superhero movie in pre-sales on ticket retailer Fandango, shattering Marvel's own record set ahead of Black Panther's groundbreaking debut in February.

Avengers: Infinity War opens April 27.