Liriano led the Major Leagues with a 2.19 ERA, statistics putting him in discussion for both the American League Cy Young and Rookie of the Year awards, but a trip to the disabled list on August 11 left him with too few innings to qualify as the league's official ERA leader and jeopardized his chances at any such awards in 2006. On August 1, 2006, Liriano was scratched from his scheduled August 2 start because of forearm inflammation after a bullpen session. He missed one start before resuming bullpen work without pain, but was placed on the disabled list after continued arm pain during his last start on August 7, 2006. Liriano began a rehabilitation program on August 22, and threw off a mound for the first time on August 30, throwing only his fastball and changeup, and said that he would like to pitch his breaking ball later that week. He made a rehab start for the Rochester Red Wings on September 9, throwing 40 pitches for four strikeouts and one walk in three shutout, hitless innings. After the game, he reported feeling no pain in his elbow and was reactivated by the Twins.