By most accounts, former LSU cornerback Tyrann Mathieu had a good showing at the NFL combine, but questions still linger regarding his off-the-field issues.

Tuesday was an opportunity for Mathieu to remind NFL decision-makers what he brings to the table athletically. He ran the 40-yard dash in a respectable 4.5 seconds and looked fluid participating in the various defensive back drills.

"I knew all along I was a natural athlete," Mathieu told the NFL Network. "That's something I do, something I work on every day. I think everything came easy today, but there's a few more drills I need to finish."

At 5-foot-9, 186 pounds, many assume Mathieu is destined to play inside, as a nickel back, but he's confident he could compete with the NFL's best on the outside.

"I feel like if I was to check somebody like a Calvin Johnson, he'll make his plays, but I'm definitely going to get mine, too," Mathieu said. "He's going to catch his five balls, but I'm going to get my two turnovers, so we'll be even."

Johnson, the Detroit Lions' record-breaking receiver, is eight inches taller and 50 pounds heavier than Mathieu. Going by the workout numbers, Johnson is also faster and can jump higher and further.

Mathieu's size didn't negatively impact him in college. In two years with the Tigers, he was a play-making machine, forcing 11 fumbles, intercepting four passes and breaking up another 19.

Still, it's a bit presumptuous of the soon-to-be rookie, who hasn't played organized football in over a year, to believe he could slow down the best receiver in the NFL. You have to admire his confidence, though.