It's another encouraging sign for Mathieu, dismissed by LSU last August due to substance-abuse issues. A failed test at the combine would have been devastating for the cornerback's draft stock.
Mathieu has been up front about his problems with sobriety during the pre-draft process. That candor was on display when an anonymous NFL assistant coach asked Mathieu how many drug tests he failed in college.
"I quit counting at 10. I really don't know," Mathieu said, according to the coach, who argued LSU is partly to blame: "If he flunked 10 tests before they suspended him, it shows that he got no kind of help."
Arizona Cardinals cornerback Patrick Peterson (who also went to LSU) has trained with Mathieu, who has worked hard to present himself as a redemption project with big upside. Mathieu is a logical fit for teams looking for a high-risk, high-reward player in the middle rounds.
Follow Dan Hanzus on Twitter @DanHanzus.