If you believe the NY Post's Page Six, the NBC Peacock is shaking in its feathers with David Muir soon taking over Diane Sawyer's slot at ABC's World News.

Page Six writes that NBC News execs are said to be worried over the imminent coronation of David Muir, who officially takes over “ABC World News” from Diane Sawyer on Sept. 2.

“He’s already knocked off Brian Williams before he’s even started,” one network veteran told me.

Muir has been filling in for Sawyer on many nights this summer, and his ratings have been just as good as hers.

Last week, when Muir was on all week, ABC had 1.764 million viewers in the key 25 to 54 demographic that advertisers care about, beating “NBC Nightly News With Brian Williams,” which had 1.687 million.

No one is panicking, a source at the Peacock Network said. “Muir has been on more than Diane all summer, so nothing will change in September. We know what we’re up against because we’ve already seen it.”