The Cardinals had evaluated the 6-foot-10 center from Upper Marlboro, Md., Riverdale Christian before the July evaluation periods but didn't jump into the mix until early August.
Less than two months after getting involved, the Cardinals landed a commitment and now a month later have the signed paperwork from Onuaku.
"It's going to be fun," Onuaku said in a recent interview. "I try to play hard all the time and coach Pitino likes that. I just go give it my all."
Onuaku said he felt comfortable with the Cardinals and the staff, noting they're going to take care of him and "make sure I improve," during his time at U of L.
Ranked as the No. 9 center in the country by Scout.com, Onuaku is tabbed as the No. 69 prospect in the country in the '14 class.
Scout.com national analyst Evan Daniels said the addition of Onuaku is a good fit for the player and for the Cardinals.
"Where Onuaku is going to help the most is by way of rebounding and shot blocking," Daniels said. "He's defensive minded, plays hard and will play the role of enforced for the Cardinals. "
Onuaku averaging 8.2 points and more than 10 rebounds as a junior in helping Riverdale Christian to the Capital Beltway League title. His stock soared after a solid NBPA Top 100 camp and stellar showings on the AAU scene with D.C. Assault.
His older brother, Arinze, played center at Syracuse. He was just released by the New Orleans Pelicans on Tuesday after spending the first seven games of this season on the roster. He played in the first two games of the season and scored three points while grabbing seven rebounds and dishing out three assists in 25 minutes.