Not just this one, but nearly every article on Hugh McElhenny I have ever seen has the line, "He was the only man ever to take a pay cut to turn pro." This piece does goes into more detail.
All of the major Pacific Coast Conference teams were operating slush funds for players in the 1950's. It became a big story in 1956 with Washington, California, USC, and UCLA the main culprits. That year several players, the most prominent USC's Jon Arnett, were only allowed to play half the season.
Usually, the head coach would stay out of the payoffs for "plausible deniability." UCLA coach, Red Sanders, made and directed the payoffs personally. Sanders was the most criticized, and UCLA received the heaviest penalties.
When McElhenny left the NFL after the 1964 season, he had no money to show for 13 years in the league. Several business ventures failed. As the article shows, he managed to do well enough in his post-football life despite this. Hugh McElhenny will be 80 years old in December.