Bill Belichick's Groan On 'MNF' Broadcast Seemingly Not Directed At Taylor Swift

Bill Belichick was clearly irked during his "Manningcast" appearance on "Monday Night Football" ... but while many believed it was a reaction to yet another Taylor Swift sighting, it actually seems like the guy was just fed up with what was happening on the field.

The legendary coach joined Peyton and Eli Manning during the second quarter of the Kansas City Chiefs' 26-13 win over the New Orleans Saints ... and in the final seconds before halftime, Patrick Mahomes and Co. drove down the field to set up a field goal.

BB let out a groan over the Saints defense's poor execution ... and the trio explained how they should have forced Kelce to the middle of the field after a catch -- instead of allowing him to get out of bounds and stop the clock.

The timing didn't do him any favors ... 'cause as soon as Belichick went "ugh," Kelce's girlfriend popped up on the screen, showing her cheering from her suite after his solid catch and run.

Some anti-Swift football fans took notice ... and quickly praised the eight-time Super Bowl champ for voicing his displeasure with the cameras cutting to the singer yet again -- but the full clip shows that doesn't appear to be the case at all.

That wouldn't make sense, though ... as Belichick is admittedly a Swiftie, and even recently rocked her merch in a pic with his girlfriend, Jordon Hudson.

In fact, Belichick didn't really seem to address Swift at all in the drive ... as he continued to talk ball before Harrison Butker's 28-yard attempt.