38-year-old heavyweight knockout artist Shane Carwin (12-2-0) has hung up his gloves recently (May 7) after back-to-back years of reoccurring injuries. Carwin received neck, back and knee surgery over the years — leaving him ineligible to compete . The former champ took to Twitter to make his announcement official.

The former top contender and interim champ looked unbeatable in his 12 fight win-streak, majority by knockout. He took out top fighters Frank Mir (KO) and Gabriel Gonzaga (TKO) before falling short in his championship fight against Brock Lesnar in July 2010. He would then only step in the cage one more time in June 2011, against now former champ Junior dos Santos (unanimous decision loss) before calling it quits.

Unfortunate for the fans, injuries have kept the explosive talent from showing his full potential, just as he reached the upper echelon of MMA competition. With an 81 second average, all with first round finished in his 12-0 start; it’s astounding to think what he would of  accomplished with more time in the sport and less severe injuries.

Photo courtesy of UFC.com