The Seattle Seahawks wide receiver will now test his speed against sprinters.
He's competing in the USA Track and Field Golden Games and Distance Open, which is Sunday in Walnut, California. USATF's website lists Metcalf among the participants in the 100-meter dash.
Metcalf hinted at this participation in the event in a tweet on Monday.
In addition to starring in football and basketball at Oxford High School in Mississippi, the 6-foot-4, 229-pound Metcalf was a standout hurdler and long-jumper.