Davis, a second-year player, was disqualified for launching with the crown of his helmet on a hit on tight end Jared Cook in the second quarter.
"I just made a tackle. There's nothing I can say," Davis said. "I just made a play. However the refs seen it is how they seen it."
Entering Week 5, six NFL players had been ejected for targeting.
In 2018, the NFL created new targeting rules that allowed officials to eject players for leading with their helmets and lowering them to initiate contact.
Davis' five penalties entering Sunday were tied for second most in the NFL.
With backup cornerback Jamel Dean also out with an ankle injury, the Bucs had to rely on rookie Sean Murphy-Bunting in Davis' absence and surrendered four touchdowns to Teddy Bridgewater, with Michael Thomas finishing with 11 catches, 182 receiving yards and two touchdowns in a 31-24 Saints win.
"It sucks not to be out there," Davis said. "This is a huge game for us, a road game, and I know that I could have impacted it."