He was a first-team Little All-American pick by the Associated Press on offense in 1968, a two-way all-conference tackle, and was selected in the third round of the 1969 NFL draft by the Baltimore Colts.

[3] The right tackle was made expendable in January 1975, however, when the Colts obtained perennial Pro Bowler George Kunz from the Atlanta Falcons as part of a trade for the number 1 overall pick in the 1975 NFL draft.

[4] Nelson reacted with disappointment to the news, threatening retirement rather than being cast into a battle for the starting left tackle job with his close friend, teammate David Taylor.

[3] Nelson spent the 1975 season at home in his native Kewanee, Illinois, running his successful livestock farm that raised and marketed about 3,500 pigs a year.

[3] The Colts then traded Nelson's contract rights to the Philadelphia Eagles, for whom he came off the bench in all 14 games of the 1976 season before seeking and obtaining his release.