Rocker struggled again in his second season in the American League, going 2-3 with one save and a 6.66 ERA in 30 relief appearances before sitting out the final two months with neck pain.
Former Cleveland Indians general manager John Hart brought Rocker with him to Texas, acquiring him last Dec. 18. But Rocker never got untracked, allowing four runs in his first two appearances of the season and finishing April with an 8.59 ERA.
Rocker, who turns 28 on Oct. 17, spent his first three-plus seasons with the Atlanta Braves and recorded 88 saves in 180 games. But he came under fire and was suspended by Commissioner Bud Selig for remarks on racial, ethnic and sexual minorities in a magazine article late in 1999.
Rocker's release came two days after the Rangers fired manager Jerry Narron.
On Thursday, Texas also announced it will not pick up the option on backup catcher Bill Haselman's contract for 2003.
Haselman hit .246 with three home runs and 18 RBI in 69 games while backing up Ivan Rodriguez, whose future with the Rangers also remains in doubt.