Lily King went from unknown to America's sweetheart in the first week of the 2016 Rio Olympics thanks to not only her gold medal performances, but also her outspoken nature against PED use by athletes. Just a few weeks later, even after a big ceremony to honor medalists from Indiana University, King walked across campus in Bloomington, Indiana almost anonymously.

King is back at school, leaving potentially millions of dollars in endorsement opportunities on the table, and there's no guarantee that she'll get them back in 2020. Missy Franklin, the golden girl of 2012, decided to go to college rather than cashing in, but a disappointing and overshadowed performance in Rio left her with whatever dollars she could get beforehand.

Why the NCAA continues to keep these opportunities from some of their best ambassadors, long after the Olympic movement itself abandoned the charade of pure amateurism, is a great anachronism. The surprise is really that athlete after athlete has actually chosen to go back to school, maintaining their eligibility and not taking the check, given the cost of training, travel, and the often large drain on their family as they work from youth meets all the way up to the pool deck at London or Rio.

King herself is young enough, much like Franklin, that she could make it through to London without issue. There's always the chance of injury or a performance drop-off, but King should, like so many athletes today, last longer than just a generation ago. However, that may not be enough. Cashing in means winning.  Even a slight step back, which could be simply losing to the next King or if Yulia Efimova comes back for revenge, means that opportunities wane.

I don't mean to suggest that King is doing herself a disservice. If she chooses to go to college and compete for her school, that's within her right. My question is why she's forced to make that decision at all.

I hate problems without a solution, so I'll suggest a very easy one. Allow NCAA athletes to cash in on their Olympic experience with endorsements but place the majority of the money in a trust for when their eligibility is exhausted. Also, put a portion -- perhaps 10 percent -- towards scholarships. Given the non-revenue status of swimming, this could go a long way to keeping the sport strong and the spots for the next King open at colleges.

By Will Carroll