He played at Thornton Township High School in his hometown of Harvey, Illinois, and led his team to a second-place state finish in his junior season.

He and his representative wrote a letter to Celtics general manager Red Auerbach asking for a two-year guaranteed deal worth $40,000.

Auerbach read the letter aloud before he tore it up while negotiating the contract of fellow Celtics draft pick Jim Barnett, who received a much lower offer.

[4] Clark spent the 1966 preseason with the Celtics and was considered a strong contender to make the final roster a month before the season began after he attempted to translate his playing position to a forward.

[5] He was cut by the Celtics before the start of the 1966–67 season and ultimately never played a game in the National Basketball Association (NBA).