Avery, a second-round selection (33rd overall) and the first wide receiver taken in the 2008 draft, was one of the victims of a crowded position for St. Louis. The speedster caught 100 passes and scored eight touchdowns over his first two NFL seasons, but missed the entire 2010 campaign with a torn ACL.
Gilyard was a disappointment after being taken in the fourth round of last year's draft, catching just six passes totaling 63 yards while averaging 22.3 yards on 16 kick returns.
The Rams kept seven wide receivers on the roster, with free-agent addition Mike Sims-Walker joining returnees Danny Amendola, Brandon Gibson, Danario Alexander and Dominique Curry along with rookie draft picks Austin Pettis and Greg Salas. That list does not include veteran Mark Clayton, who was re-signed earlier in the week but will begin the season on the physically unable to perform list.
Clayton is still recovering from a torn patella tendon in his right knee he sustained last October. Because he was put on the PUP list, he won't be eligible to play until the Rams travel to Dallas on Oct. 23.
Linebacker Zac Diles and defensive tackle Daniel Muir, two free-agent pickups by the Rams during the offseason, were also released. Diles had started 30 games for Houston over the last three years, while Muir had 38 tackles in 14 starts for Indianapolis in 2010.
The Rams also waived quarterback Thaddeus Lewis, running backs Keith Toston and Chase Reynolds, wide receiver Greg Mathews, tight ends Fendi Onobun and Demarco Cosby, offensive linemen Renardo Foster, Quinn Ojinnaka, Ryan McKee and Kevin Hughes, defensive end George Selvie, defensive tackles Marlon Favorite and John Henderson and defensive backs Tim Atchison and Jonathan Nelson.