Klug was selected by the
Tennessee Titans in the fifth round of the
2011 NFL draft, 142nd overall. In the
2011 NFL season, Klug led all rookie defensive tackles with 7 sacks, which exceeded initial expectations. On March 13, 2015, Klug and the Titans agreed to a two-year contract extension. In 2016, Klug appeared in 14 games with three starts recording 26 tackles, 1.5 sacks, and one pass defensed before suffering a torn Achilles in Week 15 and was placed on injured reserve. On March 9, 2017, Klug re-signed with the Titans. On March 17, 2018, Klug was released by the Titans. ==NFL career statistics==