Ball posted Kylie Kuzma on his social media feeds on Monday afternoon.
Kuzma and Ball were both first-round picks in the 2017 NBA Draft. Kuzma went with the No. 27 overall pick, while Ball went No. 2 overall. Ball averaged 10.2 points. 7.2 assists and 6.9 rebounds during his rookie campaign.
Kuzma posted 16.1 points, 6.3 rebounds and 1.8 assists per bout for the Lakers. Ball referenced Kuzma's birthplace and his clothing brand in the track.
"Who are you without ZO2," Ball rapped.
"Just another dude with a bunch of tattoos. You ain't got no shoe, Nike wins, Kuz lose. Claiming that I can't shoot, but all these words is hitting you. Boy you talking crazy, why you try to play me? You ain't on my level, you ain't famous as my baby. I'm working out daily, but I ain't posting it. And I would never stop a workout just to post a pic. You let 'em gas you up, thinking that you can't be touched."
"Coming from the outskirts of Flint, boy you ain't tough. Big Baller Brand getting bread, little Kuz is getting crumbs. We thumbing through that money, look at y'all, y'all playing with your thumbs. Don't know who your daddy is, well your [expletive] is getting sonned."
This isn't the first time Ball and Kuzma have playfully taken jabs at each other. In December, Kuzma posted a photo pointing to the Big Baller Brand logo on one of Ball's hats.
"Y'all really spending $600 for this," he asked, referencing Ball's signature shoes, which retail from about $500 to $700.
Kuzma included some trash can emojis on that post. He later began selling shirts with the "Kuzmania" logo on his own website.
Ball and Kuzma are both signed through 2018, with team options for 2019 and 2020. The oldest Ball brother is expecting his first child on July 16.