CHICAGO -- Oakland A's reliever Ryan Cook has been removed from the closer's role, at least temporarily, by manager Bob Melvin.
Melvin said he wanted to get the rookie some work in lower-pressure situations.
Cook has converted just two of his past six save opportunities, and 12 of 19 for the season.
Melvin was reluctant to name a new closer, saying the team has "a couple different options," including relievers who have helped close games this year.
Right-hander Grant Balfour is the only other Oakland pitcher with multiple saves. He went 7 for 9 in save opportunities before losing his job in May.