Gruden complimented Bryant for showing "what he's capable of doing" during Wednesday's practice with the Detroit Lions while quarterback Derek Carr went a step further with his praise.
"You can definitely tell that he has a sense of urgency for him to pick things up and learn them," Carr said of the 26-year-old Bryant, via NBC Sports Bay Area. "He wants to do right, he really does. To see that in him, to see him continue, he always practices hard, that's never a question. He's going to practice hard. And usually that's the hardest part to get someone to practice hard, but he is. No problem practicing hard and going hard.
"In the film room and in the playbook is where he's really working hard and he's gotten a lot better."
Carr's words were significantly kinder than the ones Gruden shared with the media last weekend on Bryant, who was acquired by the Raiders from the Pittsburgh Steelers in April in exchange for a third-round pick of the 2018 NFL Draft.
"He's got to get out here and play better," Gruden said Saturday, via the Las Vegas Review-Journal. "He's in a competitive situation. Right now, a lot of the other receivers have had a nice camp.
"He's just got to learn the offense. He's got to stay out here. He's had some illnesses. He's got to get on the field. He's got to master the offense and become more versatile, and that's the key to making this team better."
Bryant is expected to be an integral part of Oakland's wide receiving corps that includes Amari Cooper as well as free-agent signee Jordy Nelson.
The 6-foot-4, 211-pound Bryant was suspended for the entire 2016 season due to multiple violations of the league's policy on substance abuse.
Bryant returned from his year-long banishment and tied a career high with 50 receptions for 603 yards and three touchdowns in 15 games with the Steelers.
A fourth-round pick out of Clemson in the 2014 draft, Bryant scored eight touchdowns on only 26 receptions as a rookie, averaging an eye-popping 21.1 yards per catch.
Bryant followed that up by hauling in 50 receptions for 765 yards and six scores during his sophomore campaign.