Pedzisa mutsara unotevera: Munguva yemwaka wake miviri muStanstead, Jankowski akakurumidza kukura pakureba, achikura kusvika pa 6'2" pakureba, nepo kwaiva kutamba kwake kwakabata ngwariro yevasori. Akazosarudzwa mu2012 OHL dhizaini, yakatorwa seye 11th pick mumutambo wechinomwe neSaginaw Spirit kunyangwe akaramba kujoina timu. National Hockey League's (NHL) Central Scouting Bureau yakaronga Jankowski seye 43th yakanakisisa tarisiro ye
2012 NHL Entry Draft mukunyorwa kwayo kwekupedzisira, kuvandudzwa kubva kunzvimbo yake yechi74 mumishumo yapfuura. Vamwe vaongorori vakamuisa panzvimbo yepamusoro, kubatanidza Craig Button weThe Sports Network, uyo akamugadza panhamba 41. Calgary Flames yakamusarudza mumutambo wokutanga, wechi21. Iye ndiye akasarudzwa zvikuru kupfuura vose vakambosarudzwa pachikoro chesekondari muCanada. The Flames vakagamuchira vamwe kutsoropodzwa kuenda "kure bhodhi" uye kusarudza Jankowski zvakanaka pamusoro ake kutarisirwa kunyorwa nzvimbo, asi mubatsiri maneja mukuru John Weisbrod akataura kuti apo tarenda Jankowski akanga "mbishi", zvimwe zvikwata vaiva nechokwadi kuti kumusarudza rokutanga rwakapoteredza kana Flames haana. Mutungamiri mukuru Jay Feaster akataura kuti Jankowski aiva mumwe wevatambi vane tarenda zvikuru varipo muhurongwa. Panguva yokunyorwa kwenhamba dzake dzomuviri dzaiva 6'2.5", 168 pounds.