Former Batman Michael Keaton is supporting the contentious casting of Ben Affleck as Batman in director Zack Snyder's Man of Steel sequel.

Keaton famously played the Caped Crusader in Tim Burton's two well-received Batman (1989) and Batman Returns (1992) movies and most recently starred in the RoboCop remake.

During an appearance on US daytime show Today on Tuesday (March 4), Keaton backed Affleck, whose casting in the iconic role was largely met with a negative reaction from hardcore fans.

“He's going to be great,” Keaton insisted. “I don't follow it much, but I guess there was some sort of . . . I don't know why people get excited about things. Frankly, I don't understand it.”

Keaton isn't the first Batman-related actor to back Affleck. He previously received the support of Dark Knight trilogy star Gary Oldman, who played Jim Gordon. Oldman advised Affleck to ignore criticism from fans.

Batman vs Superman is due for release in May 2016.