LONDON— Sylvester Stallone may come across as the ultimate guy’s guy. But he says action stars like him are “the hardest characters to sell” to other men.

“Men are very competitive,” Stallone said ahead of next week’s premiere of “The Expendables 3.” “They go, ‘Who’s that? I’m sure he takes diuretic steroids. You know, he’s shorter than he looks.’

“It’s good to jump around,” Stallone said, “but to get other men to like you, it’s very difficult. Men are kind of stand-offish that way.”

The third installment of “The Expendables” sees the team come into conflict with a ruthless arms dealer, played by Mel Gibson. Harrison Ford and Wesley Snipes join the cast of action legends. The film opens in the U.K. on Aug. 14 and in the U.S. on Aug. 15.