Chacin, 27, threw three innings in a spring training game on Saturday, allowing four runs on seven hits.
Chacin began last season on the disabled list with a shoulder injury. He returned in May and made 11 largely ineffective starts before he was shut down for the rest of the season. He was 1-7 with a career-worst 5.40 ERA.
Chacin said the decision to release him was a surprise.
"I was kind of 50-50," he told The Denver Post. "I haven't been pitching well. I haven't been doing what I wanted to do. But I'm surprised. I didn't expect it at this time, but now I have a chance to find something else." He added that he was hopeful another team would sign him.
- Dan Gartland