Coach Chan Gailey said he didn't watch the player's workout and did not meet with Leonhard during his two-day visit. Gailey then referred questions regarding Leonhard to general manager Buddy Nix.
Nix was unavailable after the team's afternoon practice, but did say earlier in the day that Leonhard had taken his physical and was still at the Bills facility in suburban Rochester.
A person familiar with the visit said Leonhard left early in the afternoon and added that the two sides did not have any discussions about a contract. The person spoke on the condition of anonymity because the Bills have not revealed that information.
Leonhard is a seven-year veteran who spent the past three seasons emerging as a fan favorite with the New York Jets. His stint with the Jets ended this offseason, when the team did not re-sign him because Leonhard had surgery in December to repair a torn tendon in his right knee.
The Associated Press contributed to this report.