Since his retirement from the NFL, Plummer has been an avid player of four-wall handball. He attended his first professional handball tournament in 2007 when he entered the Simple Green US Open of Handball (with brother Eric) in the pro doubles division where the pair lost to future Hall of Fame members John Bike and Danny Bell. In 2008, Plummer hosted his own pro invitational and lost in the finals of the pro consolation bracket to #37 ranked, Jeff Kastner. Also in 2008, Plummer lost in the semifinals of the 2008's Idaho State Singles Championships to his brother (the eventual champion).
