Born in San Fernando, Chile, Cornejo played for his hometown's club Colchagua in the Segunda División and Palestino in the Chilean top level as a midfielder.
[1] Cornejo mainly developed his career at the Chilean top division, leading Unión Española,[2][3] Rangers,[4] O'Higgins,[5] Naval,[6] San Luis,[7] Deportes La Serena,[8] Fernández Vial,[9] Palestino[10] and Cobreloa as interim coach in 2009[11][12] and 2010, since he worked as coach of the youth ranks.
[20] Cornejo served as assistant of Luis Santibáñez in the Chile national team at the 1979 Copa América and the 1982 FIFA World Cup, in addition to the Qatari club Al-Arabi in 2000.
[23] He permanently performs as a football teacher, making courses in his homeland[19][24] and abroad in countries such as Honduras, where he worked for FIFA previous to his signing with Motagua.
[20] In 2019, Cornejo was honored due to his contributions in football by Radio Manuel Rodríguez from his hometown, San Fernando, alongside other successful sportspeople.