Marvel

It's tough to imagine anyone but Robert Downey Jr. playing Tony Stark. But in an interview published Sunday, the actor tells News.com.au that the end could be near.

"It's this cyclical thing," Downey said in the interview. "I could have said when the first 'Avengers' came out: 'It's never going to get any better than that. Everybody stop'. But to me it's always about people and opportunities, like the ('Avengers' directors Anthony and Joe) Russos, who I adore.

"Everyone says to me it's like a glove that fits so well. I have to start over every time but I am starting over with a pretty solid base. I just never want to blow it for the last six or seven (Marvel Cinematic Universe movies) I have done by dropping the ball because I decided to go do it one more time. I just want to hang up my jersey before it's embarrassing."

Downey first took on the role of Stark/Iron Man in 2008's first "Iron Man" movie, and is set to appear next in "Avengers: Infinity War," which comes out in May 2018.

The actor also praised Tom Holland, with whom he stars in the newly released "Spider-Man: Homecoming."

"Tom is the perfect man for the job," Downey said. "He's enthusiastic, bright and gifted, a very physically talented guy by virtue of his dance and acrobatic background. He has just the right combination of elements required to bring a new take on the character."