The role for which Shaffer is thus far most well-known is that of Brick Heck, a character in the American television sitcom The Middle. The role was played by Shaffer during the show's entire nine-season run, from 2009 to 2018. Brick is the youngest of the three Heck siblings, and is highly intelligent and smarter than most people his age. He loves to read and has an ongoing fascination with fonts. Brick is socially awkward, and repeatedly overlooked by the members of his family, such as via forgotten birthdays. The series and its cast were nominated dozens of times for awards, and won over a dozen collectively.