OK. How about Julius Erving? Not really recruited out of high school to a major NCAA program, he went to UMASS and had two very good seasons for a lower tiered program. He signed as an undrafted, free agent, for the Virginia Squires of the ABA and almost overnight became the face of the league. In many ways, the merger between the ABA and NBA would not have happened if it wasn't for Dr J. Of course, we all think about his later acomplishments and status, but I think he meets the criteria.
I wholeheartedly disagree with those who feel that Julius Erving fit the criteria.
He was the best high school basketball player in Nassau County in 1968 out of Roosevelt(NY). UMass in the 60's was a mecca for black ballplayers back in the day when most major colleges only recruited one or two black ball players a year. He would be followed closely by Al Skinner out of Malverne. Erving was 6-3 in high school and, like Michael Jordan, grew an additional three inches in college. At UMass, Erving accomplished the rare feat of averaging over 20-20 in points and rebounds. He was far from unheralded and far from unknown. It is true that he was undrafted by the NBA, but that was because he has not completed his eligibility, and the NBA, at the time, did not sign players who left college early. However, he was certainly drafted by the ABA Virginia Squires(Charlie Scott, Doug Moe, Mike Maloy, George Gervin, Ray Scott, Fatty Taylor).
He was the face of the league, but he did not come out of nowhere, he was a star at UMass, he started for the Squires from day one, was a star from day one, and was the brunt of more than his deserved share of criticism for a style of play that was new, different, and unattainable for those with average sized hands and leaping ability.
I remember a game at Island Garden in 1971 when Erving picked up a loose ball in a scrum along the left baseline, then without gathering himself. just leaped into the air, ball in one hand, leaped t0 the right side of the basket and threw it down; an incredible dunk. One of my top three in game dunks. Dr. J has had more celebrated dunks, but I had a very good look at that dunk from the baseline. It has not been duplicated.