Reimer began the 2011–12 season as the starter going 4–0–1. He suffered an injury on October 22 in a game against the Montreal Canadiens. During the game, Reimer was run into by Brian Gionta—he finished the first period, but did not return after the intermission. The team called the injury whiplash despite rumours that he was suffering from a concussion. Reimer missed 19 games with the injury, and struggled upon his return, yielding some starts to Gustavsson. After recording two back-to-back shutouts on February 1 and February 4, Reimer seemed to have solidified the starting position once again.