By TMZ Sports

Rap star Lil Wayne's got another one ... not a rap hit ... but another huge athlete for his Young Money APAA Sports & Entertainment Agency, this time signing an undefeated rising star the team ... TMZ Sports has learned.

Lubin is fighting champion Jermell Charlo at the Barclays Center on October 14 and recently struck a pose with Young Money president Mack Maine, the guy responsible for bringing him to the team.

This is a huge move into boxing for Young Money, Lubin is a budding superstar and if he beats Charlo -- who's undefeated, too -- could be in line for some huge money fights.

Lubin, 21, is nicknamed "The Hammer'' because of his power in both hands and his ability to bring a quick conclusion to every match. Lubin, of Orlando, Fla., has picked up 10 victories since the beginning of 2015, including seven knockouts on his way to contender status. Lubin most recently scored a sensational knockout of Jorge Cota in a title eliminator in March at Barclays Center. 

Charlo, of Houston, Texas, will be making the second defense of his title, which he won by knockout victory against John Jackson on May 21, 2016. The 27-year-old Charlo successfully defended the title with a highlight reel knockout victory versus fellow Texan Charles Hatley on April 22 at Barclays Center. He and his twin brother, Jermall, both held 154-pound world titles, before Jermall relinquished his title to move up to 160 pounds. Charlo now trains in Dallas with Derrick James, trainer of world champion Errol Spence Jr. 

"Lubin is young and hungry and I know he always comes to fight, but there's a reason why I'm where I am in the sport," said Charlo. "I've been through the trenches and I don't plan to stop anytime soon. This is what boxing always needs -- two young, undefeated fighters willing to risk their '0'. But I think it's a little early for Lubin to step in the ring with me, and I plan on keeping my title. October 14 I'll show everyone why I'm a world champion."