United Kingdom, July 21 -- The Scrubs revival cast is undergoing a major shakeup with Neil Flynn back as a recurring star and Joel Kim Booster leaving.

The beloved sitcom returned earlier this year with Zach Braff (John 'JD' Dorian), Donald Faison (Christopher Turk) and Sarah Chalke (Elliot Reid) taking centre stage as series regulars alongside a host of fresh and returning characters.

Now, it's been confirmed that the trio will be back, but there will be plenty of changes.

Ava Bunn, who played newcomer Sam Tosh in the first season of the revival, has been promoted from recurring to series regular.

Flynn's Janitor only appeared in a couple of scenes for the season one finale, but he'll be back in a recurring role, while Rachel Bilson'...