Basketball superstar Tristan Thompson has requested the legal guardianship of his younger brother Amari, nine months after their mother Andrea's heartbreaking passing in January this year.The sportsman, 32 - former flame of reality star Khloe Kardashian and father of her two children, daughter True, five, and son, Tatum, who she welcomed last year - became Amari's primary caregiver immediately upon Andrea's death earlier this year. She died of a heart attack at her home in Toronto.The NBA star is understood to have filed legal documentation yesterday (8 September), in which he requests the sole legal guardianship of his 17 year old brother.