Some NFL executives "expressed concern" about DeAndre Hopkins' "practice habits," The Athletic's Tim Graham reported Thursday.
Hopkins was released by the Arizona Cardinals on May 26 after he skipped voluntary team activities in Tempe earlier that month.
Last season, Hopkins was suspended six games for violating the NFL's performance-enhancing drug policy. He missed two additional contests because of injury but remained Arizona's top receiver with 64 catches for 717 yards and three touchdowns.
The Buffalo Bills and Kansas City Chiefs are reportedly interested in pursuing Hopkins, per SI.com's Albert Breer.