Richardson elected to become a free agent Thursday, Charlie Goldsmith of Fox 19 Now Cincinnati reports.
Richardson cleared waivers after being removed from the Reds' 40-man roster, but he's exercised his right to hit the free-agent market rather than accept an outright assignment. The right-hander holds a career 6.67 ERA and 46:39 K:BB over 56.2 innings covering parts of four seasons at the major-league level.