On his pro day, Lamar Jackson wanted to show scouts that he can make throws from the pocket in addition to his athletic ability. (1:03)

Lamar Jackson used Louisville's pro day Thursday to try to prove to NFL decision-makers that he can throw from under center, but he again declined to run the 40-yard dash.

All 32 teams were represented Thursday to watch the former Heisman Trophy winner make 59 throws, taking snaps from under center, which many NFL teams would try to have him do if they were to select him in this year's draft. He often threw out of shotgun or pistol formations with the Cardinals.

Jackson declined to run the 40-yard dash Thursday, just as he did at the combine in Indianapolis earlier this month. He told NFL Network that he decided not to run as his game tape should tell NFL teams all they need to know.

"I feel game speed is going to tell it all," he said. "You gotta catch me first. I've proved that."

Lamar Jackson tried to impress representatives from all 32 NFL teams on Thursday at Louisville's pro day. Timothy D. Easley/AP Photo

He told ESPN that he was pleased with his performance throwing the ball.

"I proved that I can throw any pass from under center," he said, adding, "I just felt I needed to show those guys that I could throw an easy ball."

Jackson won the Heisman Trophy in 2016 with 3,543 passing yards and 30 touchdowns to go with 1,571 rushing yards and 21 more touchdowns. This past season, he threw for 3,660 yards with 27 touchdowns to go with 1,601 rushing yards and 18 touchdowns. He improved his completion percentage in 2017, finishing at 59.1 after completing 56.2 percent of his passes in 2016.

Some talent evaluators have questioned whether his skill set translates to the quarterback position at the NFL level. Jackson told ESPN he doesn't let criticism bother him.

"No matter what you do in life, there's always going to be naysayers. No matter if you prove them wrong, whatever, there's always going to be negative comments," he said.