▁the ▁most ▁by ▁any ▁player ▁during ▁the ▁ 2 0 1 7 ▁NBA ▁Summer ▁League . ▁In ▁his ▁NBA ▁debut ▁on ▁October ▁ 1 8 , ▁ 2 0 1 7 , ▁Mitchell ▁registered ▁ 1 0 ▁points ▁and ▁ 4 ▁ass ists ▁against ▁the ▁Den ver ▁N ug gets . ▁On ▁December ▁ 1 , ▁ 2 0 1 7 , ▁he ▁scored ▁a ▁career - high ▁ 4 1 ▁points ▁in ▁a ▁ 1 1 4 – 1 0 8 ▁win ▁over ▁the ▁New ▁Orleans ▁Pel icans . ▁He ▁set ▁the ▁Jazz ▁scoring ▁record ▁for ▁a ▁ro ok ie ▁and ▁became ▁the ▁first ▁NBA ▁ro ok ie ▁to ▁score ▁ 4 0 ▁points ▁in ▁a ▁game ▁since ▁Bla ke ▁Griff in ▁in ▁ 2 0 1 1 . ▁He ▁sur pass ed ▁Dar rell ▁Griff ith ' s ▁team - record ▁ 3 8 ▁in ▁ 1 9 8 1 . ▁Mitchell ▁also ▁became ▁the ▁sevent h ▁ro ok ie ▁in ▁franch ise ▁history ▁to ▁have ▁a ▁ 3 0 - plus ▁point ▁game , ▁as ▁well ▁as ▁the ▁first ▁to ▁have ▁a ▁ 4 0 - plus ▁point ▁game . ▁On ▁January ▁ 4 , ▁ 2 0 1 8 , ▁Mitchell ▁was ▁named ▁the ▁Western ▁Conference ▁Ro ok ie ▁of ▁the ▁Month ▁for ▁December ▁ 2 0 1 7 ▁after ▁aver aging ▁ 2 3 . 1 ▁points , ▁ 3 . 4 ▁ass ists , ▁ 3 . 2 ▁reb ounds ▁and ▁ 1 . 8 ▁ste als