United Kingdom, April 9 -- John C. McGinley was "a mess" filming his emotionally charged scenes in the Scrubs revival.

The 66-year-old actor returned as Dr Cox in episode eight for the first time since the series premiere, and in a heartbreaking moment it's revealed the character has been diagnosed with microscopic polyangiitis, an incurable autoimmune disease.

Reflecting on the emotional conversations Dr. Cox has with JD (Zach Braff) and Elliott Reid (Sarah Chalke), John told Deadline: "Yeah, I was a mess.

"And that's not the stuff you cut in, because sometimes when the actors get too upset, it deprives the audience of sharing in that arc.

"What's in the episode is the stuff that still makes it accessible for the audience."

He credi...