Director Chad Stahelski has admitted that he was "kind of against" Keanu Reeves appearing as John Wick in the spin-off movie Ballerina.

The filmmaker has directed all four films in the main John Wick franchise, which has been so successful that it has sparked a spin-off TV series and two movies.

The first spin-off film, Ballerina, is set during the events of the third John Wick film and follows ballerina-turned-assassin Eve Macarro, played by Ana de Armas.

In an interview with The Hollywood Reporter, Stahelski confirmed that Reeves initially wasn't supposed to have a small appearance as his assassin character John, but he was later added to give Ballerina "a fighting chance".

"That wasn't in the original script. To be honest, I was kind of against it," he candidly stated. "But I do see the benefit and we wanted to help out (director Len Wiseman). We had just opened John Wick 4 and it was huge. He couldn't go back to the model of the first John Wick and do a little $18 million indie thing and try to build it up.

"In order to stay in the same game, you got to give him a fighting chance. And the easiest way to transfer that over - at least, from the studio point of view - was have Wick in Ballerina in a special timeline."

Stahelski, who served as a producer on Ballerina, also revealed that the second spin-off movie, Caine, will not feature John Wick.

However, Reeves may return to the character in a fifth John Wick film as Stahelski is "actively working" on trying to come up with a "satisfying" story after the conclusion of the fourth chapter.

"We've got a pretty good story that I think is cool. Once we have a 50-page book, and if we're feeling it, we'll sit with Keanu and shape this thing. Look, everybody seems to want it. It's a matter of whether we crack it," he said, adding that the studio wants them to "really try" to make it happen.

Ballerina is in cinemas now.