A veteran of 685 career games, the 35-year-old Strathroy, Ontario, native has opted to stop playing rather than put his future at risk with another bad hit.
"It's unfortunate the injury is going to force him to retirement," Blues general manager Doug Armstrong told ESPN The Magazine. "But when I look back at what he accomplished, where he came from, becoming a Stanley Cup champion and a dynamic player with upper-echelon speed -- he did what we all hope to do, he maximized his talent."
McDonald missed 74 games from 2010 to 2012 due to two concussions.
The news of McDonald's retirement was broken by TrueHockey.com, with McDonald saying he may have a few good years left of hockey but because of his health, it wasn't worth the risk.
"The last few years, too much of the focus became worrying about the next hit," McDonald told TrueHockey.com. "I was always thinking about it."
McDonald won a Stanley Cup with the Ducks in 2007 after signing with Anaheim as a college free agent following four years at Colgate. He retires with 182 career goals and 307 career assists in 12 seasons with the Ducks and Blues.