"Dark Phoenix" has also been pushed several months, but sources say that's just because of standard blockbuster reshoots.

Update, March 28: A source close to production tells IndieWire that the amount of reshoots required on “The New Mutants” is not finalized yet since writer-director Josh Boone has not begun writing new scenes. The source maintains Fox and Boone are in a good place. IndieWire has reached out to Boone for comment.

Earlier: “X-Men” fans received some troubling news when 20th Century Fox announced two of the franchise’s upcoming tentpoles, “Dark Phoenix” and “The New Mutants,” were being pushed back from their current release dates. “Dark Phoenix,” which finds Sophie Turner reprising her role as Jean Grey, has moved from November 2 to February 14, 2019. Fox has had great success with the “X-Men” franchise over Valentine’s Day weekend, having opened “Deadpool” to $132 million in 2016.

The “Dark Phoenix” delay is not a sign of trouble for the franchise, according to a new report from Collider. In keeping with the tradition of many blockbusters, the film recently had a test screening to see what was and wasn’t working story-wise and will undergo additional photography and reshoots to help strengthen the plot. Because “Dark Phoenix” features a large ensemble cast with numerous A-listers, including James McAvoy, Michael Fassbender, and Jennifer Lawrence, the earliest everyone can come together is August or September. Moving the release from November to February 2019 allows for enough time for filming and post-production.

The situation is a bit more hectic for “The New Mutants.” The Josh Boone-directed film was originally set for release next month (April 13), but now it has been delayed twice. Fox originally moved the release to February 22, 2019, but with “Dark Phoenix” now moving to that month, “New Mutants” won’t premiere until August 2, 2019. Sources confirm to Collider the rumor that the film will undergo reshoots to introduce an entirely new character. The source says a recent test screening for the film went well, although Fox reportedly wants it to be even scarier.

Collider reports that at least 50 percent of “New Mutants” needs to be reshot. There could be as many as two new characters being added, and both are more than just a cameo. The new characters are fully integreated into the entire story, which is why the release date has been so dramatically pushed. The reshoots for “New Mutants” are expected to be way more extensive than your average blockbuster.

Most of the cast and crew have stayed mum on the fate of “New Mutants,” but co-star Anya Taylor-Joy did express some worry with the delays in an interview with The Playlist last month. The actress called the film’s delay “frustrating” and “disappointing,” but she maintained that reshoots are ultimately a good thing because they represent a chance to make the film stronger.

“I do think that there is a great responsibility to make sure the movie is done right and that we deliver the fans something that they can all feel happy about and excited about,” Taylor-Joy said. “So, I don’t think it being delayed is a bad thing because it’s definitely more important to make sure that we get it right than rushing to make a date. So, hopefully, all of these reshoots and adding of the new character that will give the fans an altogether satisfactory, wonderful product.”

Fortunately, 20th Century Fox has “Deadpool 2” ready for release on May 18, which means the studio has at least one “X-Men” tentpole for 2018. Head over to Collider for more details on the release date changes.

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