Sylvester Stallone has said he would welcome Dwayne "The Rock" Johnson into The Expendables.

The Hercules and Fast And Furious star has hinted he would like to join the action franchise, but as a rival to Sly's team of mercenaries, which includes Jason Statham, Terry Crews and Dolph Lundgren. He previously said in a Reddit Ask Me Anything chat: "I don't want to be on their team and be buddies with them. I want to hunt every single one of them down..."

Sly said: " The Rock would be fantastic. I think he would be more of a guest villain or he would have his own group like Arnold (Schwarzenegger) - Arnold's like a competitor mercenary."

The filmmaker, who co-wrote and co-produced the films, already has some ideas for The Expendables 4.

He teased: "There seems to be a lot of unrest in certain hotspots in the world. That's what we'll focus on."

Harrison Ford, Antonio Banderas, Wesley Snipes and Mel Gibson have joined the star-studded cast of The Expendables 3, alongside a younger generation of stars such as Kellan Lutz, Ronda Rousey and Victor Ortiz.

"It's a circus, it really is a high concept," said Sly. "And the thing now is, what's next? Do you keep raising the bar? Pretty soon, there'll be no room on the poster. It should be a fold-out poster."

The Rambo actor said there could be a number of spin-offs featuring the young guns, Terry's character Hale Caesar and Antonio's alter-ego Galgo.

"The young Expendables could go on their way, Antonio could have his brief and Hale Caesar... Then you bring us back for the 'big' event. That was a pipe dream. It may still come to fruition, it may still happen," he said.

:: The Expendables 3 opens in cinemas on August 14.