to face Cain Velasquez on May 25, 2012, at UFC 146. However, on April 20, 2012, Dana White announced that Mir would face Brazilian Junior dos Santos for the UFC Heavyweight Championship, replacing kickboxer Alistair Overeem. On May 11, 2012, UFC Primetime returned to promote the fight between Mir and dos Santos, and concluded on May 25. In their fight, dos Santos was able to use superior foot work to strike in and out before Mir could mount any significant offense. Mir lost the fight via TKO in the second round and said he would have to go back to the drawing board to continue his career. Later in 2012, the UFC announced that Mir had been given a one fight sabbatical to compete under the Strikeforce banner to challenge Strikeforce Heavyweight Grand Prix Tournament Champion Daniel Cormier. The bout with Cormier was expected to take place on November 3, 2012, at Strikeforce: Cormier vs. Mir. However, on September 19 it was revealed that Mir suffered an injury in training and was forced to pull out of the bout. The bout with Cormier was rescheduled for April 20, 2013, at UFC on Fox 7. Mir lost the fight by unanimous decision. Mir faced returning former UFC Heavyweight Champion Josh Barnett on August 31, 2013, at UFC 164. Mir lost via TKO in the first round. Mir was scheduled to face Alistair Overeem on November 16, 2013, at UFC 167. However, the pairing was moved to February 1, 2014, at UFC 169. Mir lost the fight via unanimous decision. Mir was expected to face Antônio Silva on February 28, 2015, at UFC 184. However, the bout with Silva was moved up a week and served as the event headliner for UFC Fight Night 61. Despite being the betting underdog, Mir won the fight via knockout in the first round, dropping Silva with a left hook and finishing him with a barrage of ground and pound. Subsequently, Mir won a Performance of the Night bonus. Mir faced Todd Duffee at UFC Fight Night 71 on July 15, 2015. He won the fight via knockout in the first round after dropping Duffee with a straight left. Referee "Big" John McCarthy immediately stepped in to stop the fight as Duffee face planted onto the mat. Mir earned his second consecutive Performance of the Night bonus. Mir faced Andrei Arlovski on September 5, 2015, at