It looks like we're going to have to wait even longer for CBS's upcoming Star Trek Discovery series, as the production's showrunner, Bryan Fuller, is stepping back. He will however still remain the show's executive producer. Variety reports: The decision was made late last week to hand the day-to-day showrunning reins to "Star Trek" exec producers Gretchen Berg and Aaron Harberts as "Discovery" gears up for the start of filming next month and a May 2017 premiere date. Fuller, who will remain an executive producer, will still be involved in breaking stories, and the show will continue to follow his vision for the universe that this latest "Trek" series will inhabit. Writer-director Akiva Goldsman is also expected to join "Discovery" in a top creative role. He's envisioned as serving as producing support for Berg and Harberts, Fuller and exec producer Alex Kurtzman as they juggle the demands of the series that CBS is counting on to be the marquee selling point for subscriptions to its CBS All Access SVOD service. Sources said there had been some strain between "Star Trek" producer CBS Television Studios and Fuller over the progress of production on the show, as Fuller is also juggling the final weeks of shooting and post-production duties on Starz's upcoming drama "American Gods" and prepping a reboot of "Amazing Stories" for NBC. Fuller has penned the first two scripts for "Discovery" and has hammered out the broader story arc and mythology for the new "Trek" realm. But it became clear that he couldn't devote the amount of time needed for "Discovery" to make its premiere date and with production scheduled to start in Toronto next month.