One of the NFL’s top unsigned cornerbacks has been left wallowing on the free-agent market, and now there’s a clear reason why.

Veteran Morris Claiborne has been suspended four games for violating the league’s substance abuse policy, according to NFL Network. He is appealing the suspension and could get it reduced.

In a league that’s in a constant demand of capable corners, the suspension likely explains why a player with his experience was left unsigned well into training camp. Claiborne made a couple of offseason visits, most recently with the Vikings, but has been left without an employer.

A former Cowboys first-round pick, Claiborne has been somewhat of a disappointment. The 29-year-old was plagued by injuries during his five seasons in Dallas before spending the past two seasons with the Jets. Claiborne started 30 games during his tenure in New York, tallying 57 tackles, 14 passes defended and two interceptions in 2018.