Nana Visitor was worried when Michael Dorn joined Star Trek: Deep Space Nine

When Denise Crosby left Star Trek: The Next Generation in the first season, Michael Dorn's character, Worf, moved into the position of the Chief of Security of the Enterprise. It was a natural progression as Worf had been working under Crosby's Lt. Tasha Yar. And Worf remained in that position throughout the entirety of the series and the continuing movies.

In 1995, Dorn joined Star Trek: Deep Space Nine for the series' fourth season. It wasn't news that was revealed to the cast beforehand. In fact, Nana Visitor, who play Major Kira, on the series, learned about Dorn's role during a fan convention. And the knowledge made her nervous because Crosby had said that "every time I was there, Worf is looking over my shoulder."

In an interview with Trekmovie, Visitor shared that she knew fans had an issue with her character so she worried that Major Kira might be on the chopping block, so to speak. "And sure enough, he takes over when she’s gone. And I thought I may be in danger. I knew that the audience had some issues with me, and I was worried," Visitor said.

Her concerns could have been allayed had the producers informed the cast that Dorn would be joining. "And so what would it have done to have the conversation, to know, would it have made me feel a part of a team? It would have made me want to help the show in any way, to be included, and it would have stopped me from spending part of my brain worrying about that instead of doing my job," Visitor added.

Initially, fans did have a problem with Major Kira as they thought she came across as too abrasive and unlikeable. Prior to the inclusion of Major Kira in Deep Space Nine, the other women in Star Trek had been more approachable. But Visitor's character was deliberately established as a woman carrying a heavy load of guilt and anger, and it made perfect sense that Major Kira would be on edge.

Over the course of several seasons, the character grew on fans and even became a role model for young viewers. She stood out as a woman who stood up for what she believed in, defended what she loved, and didn't back down from danger, even if her own life was at stake.