Now NBC is rumored to be mulling a similarly bold move to revive ratings on a night it long dominated but in recent years has fallen way behind.

The big change: Sliding “Heroes,” the season’s top-rated new show among adults 18-49, into the 10 p.m. timeslot the long-fading “ER” once ruled as TV’s most-watched show. “Heroes” currently airs Monday at 9 p.m.

If this rumor is true, the move would be announced on Monday at the network's upfront schedule presentation to media buyers.

The network is expected to once again rely heavily on new dramas, with only two of its highly touted bunch from last year returning and at least five new ones on tap for next year. Its strategy: Concentrate on quality, and assume viewers will eventually discover good programming. That also means a number of lower-rated older shows, such as "Crossing Jordan," will be purged.

"Heroes" was one of last year's new programs, and at some levels, moving it to Thursday would make sense.

“It’s the same type of show [as ‘Grey’s’], which was a hit new show last year when they moved it,” says one media researcher. “It’s a very young show that’s created appointment viewing. If you were to pick a hit show that could move, I think that might be it. Otherwise, there’s not too many top-rated shows out there that are new and could move around.”

The move would give NBC the dominant Thursday presence it’s been lacking since “Friends” left three years ago.

Further, the competition in the timeslot is the weakest of any hour on Thursday night. ABC cycled several shows through the slot, none of them gaining much traction. While CBS’s “Shark” performed decently among total viewers, the network is expected to replace it with a new show that can better hold “CSI’s” lead-in audience among 18-49s.

Yet further, moving “Heroes” also would allow NBC to move “ER,” which has been fading all season but is still higher-rated than most of its dramas. By putting that show on another night, perhaps Wednesday, NBC could see gains on two evenings.

But of course NBC could decide to keep “Heroes” where it is, and it would have good reasons for doing so.

The show’s ratings have slipped after a two-month batch of reruns, and the network may be reluctant to dismantle its most successful night.

There's also the concern that ABC might schedule its new “Grey’s Anatomy” spinoff Thursday at 10, which would suddenly make that timeslot a lot tougher.

In any case, whether “Heroes” moves to Thursday or not, the bulk of NBC's comedy-heavy Thursday schedule is expected to remain intact when the network releases it on Monday.

Though NBC’s comedy lineup has drawn low ratings, it indexes very highly with affluent viewers, and it has won the respect of media buyers. Many praise “My Name is Earl,” “The Office,” “30 Rock” and “Scrubs” as the funniest comedy lineup on any network since the 1980s.

“Really, it’s the type of night for NBC that doesn’t necessarily deliver the quantity of viewers but the quality,” says the media researcher. “They may keep it intact.”

The one show in danger of being canceled or perhaps returning at midseason is “Scrubs,” which has hit season lows recently and has become very expensive to produce with star Zach Braff’s recent salary bump. NBC may try new comedies “Lipshitz Saves the World” or “The IT Crowd,” both getting positive buzz this week.

NBC has loaded up on drama pilots to help boost its fourth-place season-to-date 3.1 rating in 18-49s. “Lipstick Jungle,” about three women executives, “The Bionic Woman,” a remake of the 1970s show, and “Chuck,” about a computer whiz, reportedly have received orders, as have time travel drama “Journeyman” and “Life,” about a police officer.

As expected, yesterday the network renewed low-rated first-year drama “Friday Night Lights,” rumored to be moving from Wednesday to Friday.

“Law & Order” and “Law & Order: Criminal Intent” are still under consideration but probably will not return because they are too expensive. “L&O: Special Victims Unit” has already been renewed and should remain on Tuesday, with two new dramas airing before it.

NBC has also renewed “Medium” and “Deal or No Deal,” with speculation that the former could return to Mondays after struggling on Wednesday. “Sunday Night Football” will return in the fall with a revamped pre-show.

And Donald Trump’s “Apprentice” could return, but likely at midseason. Though Trump has been claiming the show was renewed, NBC has not confirmed it.

“Crossing Jordan,” “Studio 60 on the Sunset Strip” and “The Black Donnellys” will all be canceled.