The Philadelphia native and industry veteran was rushed to the hospital Wednesday for kidney failure, reports say.
Freeway, real name Leslie Edward Pridgen, was scheduled to headline FREE FEST on Saturday at the Electric Factory.
Boom 107.9 announced Friday Wu-Tang Clan member Raekwon has stepped in to headline the music festival.
Freeway thanked his fans on Twitter from a hospital bed for their continued support saying he was doing much better, and as "soon as I'm 100 (percent) #FREEFEST is back on."
Freeway's manager spoke to Action News Friday and said the rapper has undergone two dialysis treatments, and is doing well.
FREE FEST is an outdoor festival that features vendors, a DJ showcase and musical performances by popular, local hip-hop artists.