Breaston's agent, Eric Metz confirmed to The Associated Press that Breaston would not be returning to the Arizona Cardinals.
Breaston caught 187 passes for 2,528 yards and seven touchdowns in four seasons with the Cardinals. In Arizona's Super Bowl season of 2008, he had career highs of 77 catches for 1,006 yards. Bothered by a knee injury much of last season, Breaston caught 47 passes for 718 yards.
Chiefs coach Todd Haley is Breaston's former position coach in Arizona.
Breaston's departure leaves the Cardinals without a consistent receiving threat alongside star Larry Fitzgerald.
Information from The Associated Press contributed to this report.