Aaron Carter Shoots Down Dykstra Fight, Wants Soulja Boy, 'I'd Rip Him Apart'

A fight between Aaron Carter and Lenny Dykstra is NOT gonna happen ... so says the singer himself, who tells TMZ Sports the ex-baseball star is too old and fragile to step in the ring with him.

As we previously reported, the former All-Star slugger called out the pop star earlier this week ... saying, "I'm gonna f***** take this mother f***** apart piece by piece, okay?"

But, Dykstra's not gonna get that shot ... 'cause AC says he has too big of a heart to fight a 58-year-old man.

"You’re a baseball player, you’re older, thank you, but no thank you, because I don’t want to hurt you permanently or badly," Carter tells us.

But, someone who ISN'T old and fragile?? Soulja Boy ... and AC is extending an official challenge to the rapper to an epic celebrity boxing match!!!

"Honestly, I would call out somebody, I would probably call out Soulja Boy, but I would rip him apart," he said.

"Here’s the thing -- he just won’t respond. Because a lot of these guys in the industry, that do the same thing I do, they almost like to pretend I don’t exist."

"And, that’s because my record sells, and my numbers, and my concerts, and 26 years of longevity scares them, it threatens them."

Remember, Carter lasted nearly 2 rounds against Lamar Odom earlier this year ... before the ex-NBA star KO'd the singer.

AC isn't holding his breath on getting his dream opponent, though ... he thinks Soulja would be too scared to agree to the bout.

"It would be embarrassing for him because he would do a lot of talk, and say a lot of s***, and then he would be rocked apart. Because I’m a solid 165 pound man and I’m 6 foot even."