Shia LaBeouf and the rest of the original "Transformers" trilogy cast may not be returning, but director Michael Bay wants to reassure fans that the upcoming "Transformers 4" is "not a reboot."

Bay explains that while "TF4" includes new faces - including Mark Wahlberg and Jack Reynor  -- and a new "redesign" of the title 'bots, it's still part of the previous film universe.

When asked about the re-boot rumors, Bay told Forbes Magazine, "No, that's wrong. We keep the Transformers the way they were, it's just four years later. There's a reason the Transformers are redesigned. We're trying to broaden the franchise and give it more places to go,"

There will be some changes, however, including a resizing of the film's action set pieces.

"We're going to start off smaller," he continued. "There's a brand new cast. To freshen the franchise we've redesigned everything from top to bottom. The history of the first three movies is still there, we start four years later and there's a reason why we're meeting a new cast." 

"Mark is really excited about it and it's a great redesign. I said that 3 was going to be my last one. Paramount was letting me do 'Pain & Gain' and the Transformers ride was opening at Universal and it was bittersweet to think of passing it off. I wanted to set it up on a really sure footing and to bring someone else in on that, it would have been overwhelming."  

Paramount is aiming to release "Transformers 4" June 27, 2014.