By RICK EGUSQUIZA

It's Code Blue on the set of "Grey's Anatomy"!

TV's No. 1 medical drama has been plagued by infighting - and fistfighting! - all season, and now insiders say that construction of a new gym for "stars only" has created ill will between the actors and the behind-the- scenes team.

"The gym is being built on a former site where the crew gathered and stored their equipment," a set insider told The ENQUIRER. "And to make matters worse, the crew is forbidden to use the gym."

The new gym will be clearly marked "For Talent Only" - and that's not sitting well with the show's crew.

"It's a pretty obvious sign to the crew that the stars are way too important and special to have to work out with the rest of the staff," said the insider.

"It's a smack in the face to the behind-the-camera staff, and it's created bitterness that wasn't there during the first season."

As The ENQUIRER exclusively reported in October, the Emmy-nominated series made headlines after stars Patrick Dempsey and Isaiah Washington came to blows after Isaiah hurled a gay slur aimed at fellow co-star T.R. Knight.

According to the insider, tension among the actors had finally subsided, and ABC wanted to do something to "make their stars feel special."

"Adding the gym may help the cast's morale, but it's done nothing to make the crew feel better," said the insider.

"The crew is the backbone of the series, and ABC sent a clear message that they don't count as much."