It was because of bad grades, and his father was unrelenting in carrying it out.
That is the moment Ndiaye, now a senior center at Rutgers, points to as one of the reasons he is always happy, forever smiling.
"One day he just called me up and said, ‘I hope you learned your lesson,' ‘' Ndiaye said. "When I came to America, the first couple of months I was all by myself. I had no family, no language, no anything, and it reminded me of that time. I went through it, and it teaches you a whole lot of things.''
Ndiaye has been pillar of strength as the young, inexperienced Scarlet Knights (11-12) struggle through another season heading into tonight's meeting (7:30) against Division II Caldwell College, his attitude and demeanor keeping his teammates lifted.
"I'm always smiling even though things aren't going right,'' he said. "That's how I grew up to be, a strong man who really doesn't back up from anything. I've been through it all.''
The 7-foot Ndiaye arrived at Life Center Academy (Burlington, N.J.) as a non-English-speaking 16-year-old, but it didn't take him long to acclimate to a different environment.
The cold was one issue, the cultural changes another. But again, his father (Mazide), prepared him for living in a different country.
"My family is not poor,'' Ndiaye said. "But my dad kind of brought me up to have a tough childhood because all my other brothers had everything they wanted and didn't really do much with it. Since I was the youngest, he decided to change things up.
"I always thought he didn't like me. When I came to America, I realized he helped me so much. Those things he did when I was younger, the discipline, all the things he did because I thought he hated me, were because he got me tougher and to be the man I am.''
The energetic, always optimistic Ndiaye is quick to leave an impression, and his pleasant nature isn't a façade.
Junior power forward Jonathan Mitchell, who rooms with Ndiaye, said the infectious personality is ever-present.
"He smiles in his sleep,'' Mitchell said. "It keeps everybody's spirits up. His energy and enthusiasm and passion are all the time high. They say over the years he's calmed down. If you didn't know it, you'd think he was the most energetic, enthusiastic person you've seen in your life.''
Ndiaye's transformation as a boy to a man also suggests why he was able to develop into a Big East-level center. Those close to him credit his willingness to work hard and always find a positive in a situation.
The 23-yeard-old didn't begin playing basketball until he was 16, and arrived on the Rutgers as an athletic but terribly raw player. He averaged 2.7 points and 2.9 rebounds as a freshman, and was more accustomed to committing fouls (he had 57) than blocking shots (he had 49).
In fact, he averaged 4.5 points and 4.9 rebounds in his first three seasons, each of which he committed more fouls than blocked shots.
"To be successful, you almost have to have a certain personality, and that's him,'' Rutgers coach Fred Hill said. "He forever has a smile on his face. He's always nice. I've never seen him turn down an autograph request, or (not) shake a hand, or not smile at someone after a game, regardless of how we've played, how he played.
"He plays with such passion and emotion.''
Ndiaye was playing a reserve role this season, until Greg Echenique was lost to an eye injury (and subsequently transferred).
Now, Ndiaye is third in the nation in blocked shots (4.7 per game). He is averaging 9.6 points and 6.5 rebounds per game, and his play has caught the attention of NBA scouts. Last month he was invited to play in the Portsmouth (Va.) Invitational Tournament, which is for some of the top seniors in the nation.
He has blocked 108 shots and committed 65 fouls.
"He's just a great, great kid,'' Hill said. "You'd love to have 12 of him. He really wants to win. He really wants to change the culture of what's happened here at Rutgers.
"He came understanding the process and really felt like he can make a difference, and I think he has. …I think he changed the culture and the mentality, and we haven't been able to win. I think that says a lot.''
The only downer for Ndiaye is Rutgers' on-court performance. Rutgers is 43-72 in his four seasons, although it is impossible to tell from his smile and attitude.
"You have to be happy,'' Ndiaye said. "Everything is not going to go your way. That's one of the main things that I learned. You learn how to deal with it, with a big smile. Even when I'm mad, I try to smile and let it go, and smile it off.''