Creative shake-up is expected in “Castle” Season 8, as Terence Paul Winter and Alexi Hawley step in as the new co-showrunners of the popular ABC series. Nathan Fillion, who plays the titular character, has said that there is no need to worry about Kate Beckett (Stana Katic) and Rick Castle’s relationship because of the shake-up.

“Don’t be worried … Don’t be worried,” Nathan Fillion said to Michael Ausiello of TV Line. He said that when Ausiello told him that Caskett fans are worried about Winter and Hawley’s plan to shake things up and what that means for the Caskett couple. Fillion added, “It’s going to be great.”

“In order for a show to continue and to move forward, things have to change. And things have changed, every year, for these two,” Fillion said. He called the possible new developments in the new season just another change -- all part of moving forward. And, according to him, it will continue to be great.

Meanwhile, Fillion revealed that he has yet to meet the new series regular, who is set to work closely with his character in the new season. He refused to disclose any detail about the new character. Toks Olagundoye has signed on to play the new series-regular character called Hayley, a “quick-witted, free-spirited Scotland Yard police officer,” according to The Hollywood Reporter.

Hayley will be introduced as the new security specialty, and the report describes the character as someone who is not afraid to cross the lines to ensure that things are done. Moreover, she is seen as someone who is replacing former series-regular character Captain Victoria Gates, played by Penny Johnson Jerald.

Jerald’s contract was not renewed after “Castle” Season 7. Beckett is likely to don the Captain’s hat in the new season. The last season saw her passing the Captain’s exam as well as getting an offer to run for New York senate. With Captain Gates no longer occupying her office, it is expected that Beckett will decline the offer to run for New York senate and accept the Captain's reponsibility.

“Castle” Season 8 is scheduled to air on Monday, Sept. 21, 2015. Speaking about whether the upcoming season will be the last season of the series, Fillion said to TV Line that it is hard to say, adding “never say never.”

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