Top NFL prospects Calvin Johnson, Gaines Adams and Amobi Okoye reportedly admitted to marijuana use during interviews with teams in February.
Pro Football Weekly, citing anonymous sources, reported the three players, all expected to go early in the April 28 draft, made the admissions at the NFL combine during routine interviews.
On Thursday, the University of Louisville publicly supported Okoye, who at 19 is the youngest player in this year's draft.
``Amobi spoke to an NFL team in confidence and a team leaked out the information which is truly unfortunate for Amobi,'' the school said in a statement. ``Anyone Amobi has come in contact with during his time at the University of Louisville knows the character this young man has. The Cardinal football program stands behind him 100 percent.''
Ian Greengross, Okoye's agent, did not return a message seeking comment.
Okoye is a defensive end, as is Adams, of Clemson. Johnson is a wide receiver from Georgia Tech. Both Adams and Johnson were first-team All-Americans last season. Okoye made the second team.