It's been a year to "Iron Man 3" and fans of the superhero film are eagerly waiting any update on its next installment, "Iron Man 4." According to various media reports, fan-favourite Robert Downey Jr. may not reprise the role of popular "Iron Man" character Tony Stark. The role might be taken over by another actor and Colin Farrell seems to be the frontrunner in the re-casting.

Rumours swirling around suggest that "Iron Man 4" may be released before 2018, after "Avengers 3." It is also said Robert Downey Jr. may be replaced by another actor in the franchise's sequel. The actor who has portrayed "Iron Man" for almost ten years will appear in next "Avengers" movie, "Avengers: Age of Ultron." But it is not yet confirmed if he will be returning for the fourth installment of "Iron Man."

In an interview with Variety, Robert Downey Jr. was asked how many more Marvel movies there can be.

"The smart money is you have to look at everybody's age. I'll put myself at the top of the list. Sooner or later, they've got to start over and get somebody young. I'm not there with them yet," answered Robert Downey Jr.

It led to the rise of speculations if 49-year-old actor will be seen in his iron suit again or not in "Iron Man" movie. Robert Downey Jr. earned enormous fan following during his stint as Tony Stark. Whether fans will accept any other actor in his place or not, remains to be seen.

However, many media outlets are contemplating possible choices for the role. Movie Pilot conducted a fan casting survey of sorts for "Iron Man 4." According to them, the actor who could replace Robert Downey Jr. for fourth installment is Colin Farrell. They assembled 16 names and asked fans to vote for the one they think is most suitable for the role. The Movie Pilot's list included Matt Damon, Edward Norton, Ryan Gosling, George Clooney, Robert Pattinson, Jamie Dornan and more.

Earlier, Metro presented five contestants who could replace Robert Downey Jr. for his iconic role. The list included Bradley Cooper, James Franco, Elon Musk, Jon Hamm and Colin Farrell.

While comparing Colin with Robert, the Web site notes that just like Robert Downey Jr., this actor also possess the combination of "emotional vulnerability and bad-boy twinkle as his master." Pointing out at his acting skills, the publications suggested that just like Robert, 36-year-old Colin can "skip effortlessly between wry dark comedy (In Bruges) and 'proper' acting (Terrence Malick's The New World)." He is also known for his action movie "Total Recall."

Meanwhile, What Culture also gave out its list of contenders who could replace Robert Downey Jr. Among eight actors, Colin Farrell topped the list. The publication noted similarities between the two. "Farrell has a strong resemblance to Downey's Stark, filling out a suit nicely and working a very similar hair style. He also proved in In Bruges that he can spit out the rapid-fire quick-wit dialogue as good as anyone" says the Web site.

What do you think? Would you like to see Colin Farrell in place of Robert Downey Jr. as Tony Stark in "Iron Man 4?" Let us know.