No doubt there were numerous reasons why Pratt was deemed the right man to portray Star-Lord, but as Kevin Feige mentioned in the Marvel Studios: The First Ten Years book (via Comicbook.com), a big one was that they knew one day he’d be a good foil for Robert Downey Jr. in the coming years.
Before Pratt, actors like Joel Edgerton and Eddie Redmayne had tested for Peter Quill, but Pratt scored the role in February 2013, and like the other starring MCU actors, signed a multi-picture deal.
Enter Chris Pratt, who before joining Guardians of the Galaxy was best known for playing Andy Dwyer on NBC’s Parks and Recreation and had appeared in movies like Moneyball and Zero Dark Thirty, but was nowhere near a blockbuster star.