"I feel like Marcus has done everything he needs to do to get the ball to his receivers," Douglas added, via ESPN.com's Paul Kuharsky.
Douglas isn't alone in that assessment.
"No. 1, it's his accuracy," Jefferson continued. "No. 2, he's come in and grasped the offense. And No. 3 is the way the guys respond to him, the way he's able to go in that huddle and take control. ... I am just giddy about his future going forward."
As well as Mariota has performed in practice sessions, coach Ken Whisenhunt understands it means little until his quarterback faces "the A-gap blitzers" and other forms of pass rush.