Dak Prescott Taunted in Stadium Tunnel After 'Embarrassing' Loss

Dak Prescott heard some boos on the field, but never expected to get heckled walking to his own locker room ... but that's exactly what happened to the Cowboys star quarterback in the tunnels of AT&T Stadium.

"Embarrassing!" an unknown person shouted at the 33-year-old signal caller after the team's shocking 24-16 loss to the previously winless Bucs -- as he was just feet away from the Cowboys locker room.

Prescott turned his head while still walking, and stared the taunter down for a solid five seconds.

As soon as Prescott turned around and was no longer looking, the "fan" said, "He heard me."

Dak then chirped back, "You said it once I looked off, huh?"

Prescott talked about the bizarre situation during his postgame interview, explaining what bothered him about the interaction.

"When he said it, I just happened to look at him, and at that point, ya know, he looked away, didn't look, and when I turned my head back, he said something else."

The 4x Pro Bowler continued ... "Feel free to speak your mind, just speak it, don't cower away from the reaction you're going to get."

So, it's more an issue with the way it was said, rather than the actual message ... 'cause it was embarrassing for the Boys, who were something like 8.5-point favorites in the game.

Prescott's numbers didn't look terrible -- he was 24-for-42 for 316 yards with one touchdown and two interceptions -- and the Cowboys had a chance to tie things up late in the fourth quarter ... before Dak threw a game-ending pick.