Calgary failed to reach the playoffs in both seasons, and while Bouwmeester's offensive production increased in the lockout-shortened 2012–13 season—he had 6 goals and 15 points in 33 games for Calgary and again led the team in ice time—he also reached 750 career games without appearing in the playoffs. With the Flames entering a rebuilding phase, Bouwmeester agreed to waive his no-trade clause and accepted a trade on April 1, 2013. He was traded to the St. Louis Blues in exchange for prospects Mark Cundari, Reto Berra and a first-round draft pick in 2013. He described leaving Calgary as "bittersweet", calling the city a great place to play, but expressed hope he would finally reach the playoffs with the Blues. He achieved this goal after the Blues clinched a playoff spot in their third-last game of the season, and the 762nd of Bouwmeester's career. In so doing, he avoided breaking Olli Jokinen's NHL record of 799 career games before making his playoff debut (Jokinen was surpassed by Ron Hainsey two years later).