"He didn't look like he was hustling to go in for a tackle," said Arians, who had called out the entire secondary leading up to Sunday's tilt, via Jenna Laine of ESPN.
The 24-year-old corner didn't fight the assessment.
"If that's what coach saw, that's what he saw," Hargreaves said. "There's no arguing it. I need to hustle, point-blank, end of discussion. And I'll get better. I'm sure I'll talk with him this week and we'll get things straightened out, and we'll see where to go from here."
After being reprimanded early in the offseason, Hargreaves turned in a solid training camp and opened up the season well. But the fourth-year pro has returned to Strugglesville of late.
Perhaps Arians is hoping his brief benching will get the attention of the former No. 11 overall pick.
After injury struck Sunday, Hargreaves was reinserted into the tilt late and was called for defensive pass interference on a 4th-and-5 play with 30 seconds left that gave Arizona new life.
The Bucs picked up the fifth-year option on Hargreaves' 2020 contract, which is worth $9 million. The option is guaranteed for injury only. Barring a dramatic change in play down the stretch, Tampa won't want to pay that price next year for a player getting benched midway through the season.