Leading up to the NFL draft, the biggest criticism of Jackson was how precisely he delivered the ball. Jackson never completed more than 60 percent of his throws in his three seasons at Louisville.
"The thing I was really impressed with is I thought he was accurate," Harbaugh said Saturday. "You read the reports ... but he's a naturally talented thrower. He has natural arm talent. That's something that I think people were questioning. To see him out here throwing the ball naturally and very accurately, I thought it was a big plus."
Jackson's practice Saturday was an up-and-down one, which is understandable considering it was the second time he had stepped onto an NFL football field. He showed great touch on deep throws, hit fellow first-round pick Hayden Hurst in stride over the middle and sprinted past defenders after pulling the ball down. But Jackson had trouble connecting with his receivers outside the numbers, overthrowing them on out routes.
Jackson, the No. 32 overall pick of this year's draft, is focused on adjusting to a new playbook and fundamentals, which includes taking the snap under center instead of shotgun.
"I'm just trying to learn as fast as I could," Jackson said. "Just learn the ins and outs of certain techniques and the name calling of the plays."
Jackson hasn't heard from quarterback Joe Flacco since being drafted in the first round nine days ago. Asked what he would want to know from Flacco and Robert Griffin III, Jackson said, "How they see things on the field and what made them learn the system even faster."
The Ravens insist Flacco remains the starter this year, but Harbaugh acknowledged the team is working "in the laboratory" to figure out creative ways to get Jackson involved.
"We're going always try to get our players making plays for us," Harbaugh said. "And Lamar is a guy who can help us win games."
Jackson is fine being used in trick plays.
"They want me on the field to utilize my talent and be a quarterback," Jackson said. "That's cool with me."
Most of the attention in rookie minicamp was on Jackson. Eight of the 10 questions asked of Harbaugh were about the 2016 Heisman Trophy winner.
Harbaugh praised Jackson's attitude, smarts and work ethic.
"I think we all feel like he handled himself very well out there," Harbaugh said.