America's disgraced Olympic 100m champion Justin Gatlin has trained with the Arizona Cardinals, having already worked out with the Houston Texans.
Gatlin hasn't played American football since high school
The 24-year-old faces a life ban from athletics after testing positive for testosterone in April - his case goes to arbitration in the new year.
Gatlin is also set to coach at his former Florida high school.
He graduated from Woodham High School in Pensacola in 2000 and will return to coach the boys' athletics team.
Woodham boys' coach David Graves insisted they had no reservations despite the allegations against the athlete.
"For all of us it was never a question," he said.
"I don't speak for just myself but many of the Woodham faculty who have never questioned his character."
It would be a big step for him to step up and start playing football
Texans coach Gary Kubiak had previously said that offering the sprinter a contract was "not something we would do right now".
But after the training session Kubiak said: "A lot of teams in the league have worked him out over the course of the past month.
"From (general manager) Rick (Smith)'s perspective, he was very impressive.
"He did a good job (in the workout). Some of our people who were watching him were amazed at how fast he ran.
"I don't even know if he was full speed at that time. But he did catch the ball pretty good.
"It would be a big step for him to step up and start playing football, but that looks like it's something that he's interested in."
British sprinter Dwain Chambers, who served a two-year ban for a drugs test failure, has also been put through his paces at NFL training camps.