As TMZ previously reported ... Kaely -- who is battling stage 4 anaplastic large-cell lymphoma -- was invited to be Humphries' guest of honor at a Nets game ... once he found out it was her dream to hang out with the NBA superstar.

Sources close to Kris tell TMZ ... after meeting Kaely following the Nets game on April 23, he is determined use his star power to help raise money for the 16-year-old, in order to help her family with the staggering financial costs.

We're told Humphries is also excited to get the teenager to as many games as possible next season, since Kaely said the unforgettable experience lifted her spirits tremendously.