If Jake Paul can't fight Hasim Rahman Jr. on August 6, there's someone else willing to step in the ring in his place -- Hasim Rahman Sr.!!
That's right ... the 49-year-old, 2x heavyweight champion tells TMZ Sports he's down to fill in for Jr. and box the Problem Child.
Oh, and for good measure, he says he'll fight Logan, too ... same night.
"How about this?" Hasim says, "If somebody would sanction this, I will fight Jake and Logan back to back.