The New Orleans Saints tried out five wide receivers today, according to a league source with knowledge of the situation.
Hill is a former San Francisco 49ers third-round draft pick from Washington State.
He was with the Denver Broncos during the preseason.
He has caught 76 career passes for 1,028 yards and eight touchdowns.
Hill tried out for the Oakland Raiders in December.
The 6-foot, 202-pounder was cut by the Jaguars on Nov. 10 after catching a career-high three touchdowns and 367 receiving yards on 25 receptions.
With the 49ers in 2008, he caught 30 passes for 317 yards and two touchdowns.
Hill started 10 games last season before being released.
He's entering his seventh NFL season.
Robiskie is a former Cleveland Browns second-round draft pick who was last with the Jaguars and has recently tried out for the New England Patriots. Parker has caught 44 passes for 596 yards and three touchdowns for his career with the Tampa Bay Buccaneers.
Davis is a former Chicago Bears wide receiver who has caught 92 career passes for 1,095 yards and five touchdowns.
Butler is a former Seattle Seahawks player from Penn State who has caught 57 passes for 611 yards and four touchdowns.
Meanwhile, the Buffalo Bills auditioned running backs James Davis and Ed Wesley.
The New England Patriots worked out tight end Jake Byrne.
The NFL has lifted suspensions for Denver Broncos tight end Virgil Green, Cincinnati Bengals linebacker Dontay Moch, Green Bay Packers defensive end Mike Neal and New York Giants safety Tyler Sash and has granted their respective teams one-week roster exemptions through Oct. 8.