Big shakeup on the staff of NBC’s "Heroes" came down on Sunday with the axing of co-exec producers Jesse Alexander and Jeph Loeb.

Both scribe-producers had been with the show since its first season and were known to have led the day-to-day production operation under the direction of creator/exec producer Tim Kring.

"Heroes," produced by Universal Media Studios, has struggled in the ratings its third season. It’s understood that Alexander and Loeb were let go because of Peacock execs’ frustration with the creative direction of the show. The show is also said to have been grappling with hefty budget overruns this season, that are going well beyond its already sizable $4 million per-seg pricetag.

Reps for NBC and UMS declined comment.