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's hotel visitor Charlie will also appear more.

However, it's been reported that neither Joel Kim Booster (Dr. Kevin Park) nor X Mayo (Nurse Raymond) will be back for season two.

Booster's character Dr. Park had served as an antagonistic rival for JD.

Meanwhile, original series stars John C. McGinley (Perry Cox) and Judy Reyes (Carla Espinos) will both return as recurring stars, as they're filming as series regulars on Rooster and High Potential, respectively

Back in April, the Scrubs revival showrunner Aseem Batra - who also executive produces alongside the original series creator Bill Lawrence - opened up about storyline and casting plans for the upcoming second run.

She told Deadline: "Both shows have been amazing and working with us to get those performers over to Vancouver [where Scrubs films].

"So we'll do our very best to keep them in the fold, because they are part of this in a big way, but we're happy for their success in other areas, and we'd just love them back as much as we can get them."

Fans have been hoping to see Ken Jenkins, 85, return as Bob Kelso after he was absent for season one.

In February, Bill Lawrence insisted the character would "be back" after things "just didn't work out", but he's yet to be confirmed.

The official logline for the 10-episode second season has teases "some surprises" for viewers.

It reads: "J.D., Turk and Elliot have levelled up from interns to icons at Sacred Heart.

"Now, the respected doctors inspire the next generation while balancing the ups and downs of working in a hospital.

"Together with characters new and old, they are navigating this next chapter with laughter, heart and some surprises along the way."