But ever since he followed neighborhood buddy Eugene Harvey's lead last fall and left his native Brooklyn and Boys and Girls High School for Newark and St. Benedict's, it's been about adjustments, the biggest of which has been trying to transform a proven scorer into a guy that can run a team.
"Basically, I've just been trying to be more of a lead guard," said McMillan, a senior. "I know I can score but I want to be more of a pass-first guy."
That change has been born of necessity. Coming out of Boys and Girls, McMillan's game resembled that of your classic New York City scoring guard: he could drop down shots from the perimeter, get his jumper when he needed to, and his offensive instincts were keen. After the transfer, however, he needed to fine-tune his approach.
"When I was at Boys and Girls playing with Greedy Peterson, I was more of a scorer," said McMillan. "When I came to St. Benedict's, and I started playing with all of these players, that really helped (me change my approach). It was a physical thing, really. I didn't get that type of competition at Boys and Girls."
McMillan could become a hot backcourt commodity this spring. Despite being a senior, his recruitment still has a ways to go.
"I'm going to sign late," said McMillan. "I'm trying to get my grades, get my scores." Style of play will likely factor into McMillan's decision.
"I'm just looking to get to (a program) with an up-tempo style of play," said McMillan. "South Florida, Clemson, Cincinnati, and St. John's have offered me, And Miami has showed interest. ... USC has been calling me lately. They haven't offered, but they came to our school (last week) to see me and Tristan Thompson."
One school sticks out to date. "South Florida is number one on my list," said McMillan. "That's probably where I'll end up. But I'm keeping my options open. I also like St. John's. That would give me a chance to stay local."
McMillan has a fairly nuanced take on where he fits at the college level.
"(My role) will depend on the school I go to," said McMillan. "If I go to a place like South Florida, I'll probably be more of a scorer and a leader, because that's what they're looking for. If I go to a place like Cincinnati or Clemson, I'll probably have to do more defensively. I'd see how I'm doing during the (freshman) year (at those schools), and take it from there.
"I think coaches like that I'm (trying to be) a pass-first point guard. I think they like that I can play in an up-and-down game and in a halfcourt game. And my defense (and the fact that) I can pick up my man at 94 feet."