Kammala jumla mai zuwa: Rated a matsayin na huɗu mafi kyau Arewacin Amirka defenseman da NHL Central Scouting kuma duk da kasancewa daya daga cikin mafi ƙanƙanta m a shekaru, Siemens aka zaba 11th overall a cikin
2011 NHL Entry Draft ta Colorado Avalanche, tare da zaɓar da aka samu daga St Louis Blues tare da Erik Johnson da Jay McClement a musayar zagaye na biyu, Chris Stewart da Kevin Shattenkirk. A ranar 28 ga Yuli, 2011 Colorado Avalanche ya sanya hannu kan Siemens zuwa yarjejeniyar shekaru uku.