Now Jk is the loan sharks Boss target, he will do everything until Jk loses the match.
They're not going to bribe Dan, they're not going to lose money on it. They will scare Dan by kidnapping him and threatening him in exchange for Grandma's safety, Dan will do everything they say, he will be a spy in the gym and even sabotage Jk before the match, Jk loses the match, finds out that it was Dan who did it, throw Dan away.
OR
they find out they're friends with benefits cos Jk jinx and that Dan's Jk's most effective amulet and they threaten to ruin Jk's reputation if Dan doesn't disappear, hmm this plot doesn't look good, what's the author doing? new elements coming, I hope for a non-cliché plot (but it will be cliché)