Athletics release veteran reliever Santiago Casilla

OAKLAND, Calif. -- The Oakland Athletics have released veteran reliever Santiago Casilla, five days after he was designated for assignment.

The A's made the move Thursday.

Casilla is 42-31 with 144 career saves in 15 seasons, but has been up and down with the A's this year while having control issues. Used primarily in middle relief, the right-hander has a 3.16 ERA despite 20 walks and four hit batters in 31 1/3 innings. He turns 38 next week.

Casilla made his major league debut in 2004 and spent his first six seasons with the A's before signing with San Francisco in 2010. He returned to Oakland last year and had 16 saves.

The A's have used a mostly young bullpen this season anchored by rookie Lou Trivino and All-Star closer Blake Treinen.