I believe Grayson Allen became the only player besides Mitchell to score 40 or more points as a rookie for the Jazz.
https://www.basketball-reference.co...=Y&c1stat=pts&c1comp=gt&c1val=40&order_by=pts
https://www.basketball-reference.co...=Y&c1stat=pts&c1comp=gt&c1val=40&order_by=pts