Robert Downey Jr. Chris Evans. Chris Pratt. Paul Rudd. These are all names that are now associated with the growing mega-franchise known as the Marvel Cinematic Universe. What Marvel started by casting fairly unknown actors in big superhero roles has now grown exponentially. Everyone wants a taste at these movies, as they are a surefire way of making an actor much more popular among audiences. However, these brilliant actors had to start somewhere. They didn't begin their careers playing renowned members of the Avengers. Like any actor, they had to start out having some minor appearances and guest roles in small projects like TV movies. What's special about many of these projects is that it's likely no one has even heard of them, let alone the actors that starred in them.

Over time, these actors managed to build up their careers and receive a lot of praise for their performances. That's when Marvel came knocking on their doors to draft them for the most ambitious film project in history. It's a universe that keeps on growing, with new actors joining every step of the way. They all had to start somewhere, but it's unlikely you'll remember these 15 forgettable first roles of MCU actors.

15 ROBERT DOWNEY JR - POUND

Robert Downey Jr. had his foot in the door with acting as his father was a director. Robert Downey Sr. wrote and directed a movie called Pound in 1970. As a way to encourage his son to go in the family business, he had Robert Downey Jr. appear in the film as a little boy named Puppy.

All those decades ago, Downey had to be no more than five years old at the time. Having little blonde hair and a little bit of the snark that he's known for today, Robert Downey Jr. would have Hollywood's attention before eventually starring in movies like Iron Man, Sherlock Holmes, and Tropic Thunder. He definitely owes a lot to his dad and his first foray into the movie world.

14 CHRIS HEMSWORTH - GUINEVERE JONES

Guinevere Jones is an interesting TV series. Based off of a book of the same name, the show stars a girl named (you guessed it) Guinevere Jones as she is placed into foster care. Once she encounters the wizard named Merlin, he informs her that she is the reincarnation of the Queen Guinevere of old.

However, with Guinevere comes a King Arthur. Throughout the show, she has flashbacks to her past life as the Queen of Camelot with her valiant husband at her side. This is where Chris Hemsworth swoops in as the man playing the King of Camelot. He doesn't have any speaking parts, but his appearances are long enough that you can make out the award-winning smile that will come to define Thor, the King of Asgard.

13 PAUL RUDD - SISTERS

Sisters was an extremely well-received show. Getting several Emmy Award nominations, it was bound to be a classic to those who watched it. As you might imagine, big shows like it would go on to serve as a debut for many new and upcoming actors, including a young comedian by the name of Paul Rudd.

Rudd played a man named Kirby Philby, who eloped with the character Reed. Being an aspiring filmmaker, he had a lot of visions for the future. After he and Reed had a daughter together, Kirby decided to own a movie store. However, Reed was not able to cope with these changes and chose to leave Kirby in the dust, but told everyone that he disappeared and kidnapped their daughter. Eventually, though, Kirby was found and the main characters were told the truth about what happened.

12 CHRIS EVANS - THE NEWCOMERS

It's one thing to make a big acting debut as a guest role in a well-received film, but it's another thing to make a debut in a movie that wasn't well-received. Unfortunately, that is exactly what happened to Chris Evans. Before he ended up in Fantastic Four, Snowpiercer, and Captain America, he played a country boy named Judd in The Newcomers.

This movie starred a family who had a young boy that was constantly bullied. The torture got so bad that they decided to move out to the country. The teenage girl of the family ended up with Judd and they formed a relationship. There's not much else to say about the movie other than that we're glad Chris Evans did well enough to appear in future movies.

11 ZOE SALDANA - LAW AND ORDER

Law and Order, having gone on for so long, is a gold mine of guest appearances and debut roles for actors that we now know and love. Among the people who appeared on the show was Zoe Saldana, the woman who would eventually become Uhura in the Star Trek reboot and Gamora in Guardians of the Galaxy.

She appeared in 1999 as Belinca, who was involved in the investigation of a shoot-out murder case. However, she would later be a part of Law and Order: SVU as the daughter of a man who was framed for murder (she eventually sued the police department). Even back then, Saldana showed that she had what it took for more emotional roles, as was reflected in her relationship with Nebula in Guardians of the Galaxy Vol 2.

10 JEREMY RENNER - NATIONAL LAMPOON'S SENIOR TRIP

Jeremy Renner didn't always have it easy. Before he ended up playing Hawkeye in the MCU and Aaron Cross in The Bourne Legacy, he had a role in the 1995 comedy, National Lampoon's Senior Trip. Playing a kid who was a trouble-making stoner. Getting into all kinds of hijinks, it was his famous "I know you like me" scene that was particularly cringe-worthy.

Unfortunately for Renner, National Lampoon's Senior Trip was critically panned by both critics and audiences. After that, Renner had to go back to getting roles in TV shows before having a breakthrough in the movie Dahmer. Brilliantly capturing the spirit of a serial killer made him closer to a household name. That performance would lead to him playing the superhero turned family man, Clint Barton, otherwise known as the S.H.I.E.L.D archer Hawkeye.

9 SCARLETT JOHANSSON - NORTH

Scarlett Johansson is one of those women who is both alluring and exciting to watch on screen. Having appeared in big blockbusters like Lucy, The Jungle Book, and Ghost in the Shell, she has since become a household name. Making her big leap as Black Widow in Iron Man 2, she is destined to stay in Hollywood for a long time.

Her first role in a movie was a little girl named Laura Nelson in Rob Reiner's movie, North. She is barely recognizable, as she is extremely young. However, she only has a few minutes in the movie, as she is not the focus. Sadly, the movie was critically panned and some regard it as one of the worst movies of all time. Thankfully, both Scarlett and the lead actor, Elijah Wood, would later find time for more impressive and well-received projects.

8 ANTHONY MACKIE - 8 MILE

Of all the artists who tried to make a movie, no one expected the best among them to be made by Eminem. 8 Mile was a celebration and thoughtful look at what it took for a white man to become a respectable rapper, and there's a lot to love. However, it also served as the debut for Anthony Mackie, who would later play the Falcon.

What's more surprising is that Mackie wasn't in a background role. As a matter of fact, he was portraying Eminem's biggest rival in the film: Papa Doc. While we'll be indefinitely waiting to hear his rap rebuttal toward Eminem, it was interesting to see him go from a rap movie villain to a heroic and patriotic Avenger. However, his destiny is always to get beat, as he was taken down by Ant-Man and Iron Man in the span of two films.

7 TOM HOLLAND - THE IMPOSSIBLE

Tom Holland is currently the youngest main cast member of the MCU. After months of wondering who it was going to be, Marvel announced that he would be their version of Spider-Man. Wanting to have a more classic take, they needed a younger actor. Thankfully, they chose one of the best, as Tom Holland is a great actor with an impressive history.

Debuting in a live-action film in 2011's The Impossible, Tom Holland gave such an astounding performance that there were rumors floating around that he was going to be given an Academy Award. After that, his film credits grew to the point where his life was "flipped upside down" once he got the part to become Peter Parker. Needless to say, we're excited to have him on board; he's the best cinematic Spider-Man and Peter Parker to date.

6 BENEDICT CUMBERBATCH - HEARTBEAT

Benedict Cumberbatch is one of those actors that people swoon over. Now making performances in Doctor Strange, Star Trek Into Darkness, The Hobbit, and BBC's Sherlock, Cumberbatch has quickly become one of the most well-known actors. Like everyone else, though, he had to start somewhere. For him, it was in the show called Heartbeat as Charlie.

His performance in that show has garnered some criticism, and it wasn't his breakthrough performance by any means. After all, he only had a few minor appearances. His claim to fame would come in 2006 as William Pitt the Younger in Amazing Grace. From that point on, Hollywood has known how much of an excellent actor he is, and they've not hesitated to cast him in some massive projects.

5 TOM HIDDLESTON - THE LIFE & ADVENTURES OF NICHOLAS NICKLEBY

Ten years before he appeared as the God of Mischief, Tom Hiddleston made his film debut in the 2001 adaptation of The Life and Adventures of Nicholas Nickleby. As you might expect, he had a minor role in the film, serving only as an accomplice to the antagonist. He had but a few minutes of screen time in total, and didn't have much dialogue either.

However, it would serve to his benefit, as he would gain more notoriety in the years that followed. Having some acclaimed roles in 2007 and 2008, he would eventually be called upon by Kevin Feige to play Loki in 2011's Thor, which was his ultimate breakthrough role. Since then, Tom Hiddleston has been one of the biggest names in Hollywood, appearing in other popular films like Kong: Skull Island.

4 ELIZABETH OLSEN - HOW THE WEST WAS FUN

When it comes to the last name Olsen, it was immediately the twins that everyone thought of. However, there was a third Olsen who had the potential to become a rising star, and her name was Elizabeth (formerly known as Lizzie). Having made subtle appearances alongside her sisters in TV shows, her first official film appearance was as a guest role in How the West Was Fun. Credited solely as "Girl in car," Elizabeth wasn't the star by any means.

It would be over a decade later when Olsen had her breakthrough role in Martha Marcy May Marlene in 2011. After that, she immediately gained Hollywood's attention and was chosen by Marvel to play Wanda Maximoff, better known as the mentally unstable Scarlet Witch in Avengers: Age of Ultron with an end credits appearance in Captain America: The Winter Soldier.

3 CHADWICK BOSEMAN - THIRD WATCH

When Marvel wanted to bring Black Panther to the MCU, they needed someone who could portray a regal character who had a ferocious side to him. As with most of their roles, they got the perfect man for the job. Chadwick Boseman, complete with the African accent, has brought the King of Wakanda to life.

Long before he first appeared in Captain America: Civil War, Chadwick made his first appearance on screen during an episode of Third Watch in 2003. He was little more than a minor character, but it would later spawn his appearances in other shows like CSI and ER. Once he finally landed some starring roles, Hollywood paid attention to him and Marvel was ready to knock on his door, offer a serious amount of cash, and draft him to the Avengers.

2 CHRIS PRATT - THE HUNTRESS

Chris Pratt is one of Hollywood's lovable dorks, gaining serious momentum in projects like Parks and Rec. However, before he was Andy Dwyer, Peter Quill, or that guy in Jurassic World, Chris Pratt appeared in an episode of The Huntress. He was only in it as a guest appearance and didn't have any lasting impact in the show.

Nonetheless, he started to grab people's' attention when he became a series regular for the show Everwood. Once it got canceled, he moved forward to the point where he was drafted to play Star Lord in Guardians of the Galaxy. Fun fact: he actually turned down the part when it was first offered to him, but changed his mind when he met James Gunn -- the director of the film.

1 SEBASTIAN STAN - TONY N' TINA'S WEDDING

Sebastian didn't have a long career before he was cast as Bucky Barnes in Captain America: The First Avenger. He had a few minor TV roles here and there, but his film debut role was in Tony 'n' Tina's Wedding as Johnny. Playing a drunken party boy who's just along for the ride, it's definitely jarring to see Stan in that movie considering his more grounded work now.

He would later appear in other noteworthy projects like Hot Tub Time Machine and Black Swan before being called to the MCU. After seemingly dying in the field, he would be salvaged by HYDRA to become the mysterious assassin known as the Winter Soldier. While there was some doubt that Stan could pull it off at first, he portrays the character expertly, giving us one of the most tragic personas to date.