KNOXVILLE, Tennessee  _ Olympic sprint champion Justin Gatlin showed off his skills to NFL scouts during the University of Tennessee's pro timing day on Wednesday.

Gatlin is the reigning Olympic 100-meter gold medalist. He received a potential eight-year ban for doping violations, but that ban was reduced to four years.

He is appealing the ban in hope of voiding the first of his two doping violations to be allowed to compete this summer in the Beijing Games.

Gatlin tested positive for excessive levels of testosterone at the Kansas Relays in 2006, his second doping offense. The first came in 2001 when Gatlin tested positive for amphetamines, part of a prescribed medication he was taking for attention deficit disorder.

Gatlin was among 14 former Tennessee players to participate in the pro timing event, which was closed to the public.

The NFL draft is from April 26-27.