Professional athletes are paid according to how much income they bring that league and team. The better the player, the better the revenues. So no, they are not over paid. If the team is making money off them, they should be paid accordingly.

From a personal viewpoint, athletes are overpaid. No doubt, but the market views it from a different standpoint.

From a economic viewpoint, athletes are paid quite nicely because of three reasons:

1. Supply and Demand of the Labor Market

For example, Alex Rodriguez earns ~$25 million dollars a year. In 2009, Alex hit 100 RBI, 30 Home Runs, 127 Hits, .286 Batting Average, and .586 Slugging while missing the first month of April and leading the Yankees to the World Series. Now, the supply who can produce this is very limited, it is basically only Alex. However, the demand is skyrocketing. Every team wants Alex, but since the supply is very low, he will demand a high salary. Thus, the Yankees are the only team that can afford his talent.

2. Mass Consumerism

Sports is a very consolidated. Meaning that of all the teams, they may be 10,000 employees in each sport. However, they are bringing in billions of dollars of revenue in mass consumerism from tickets, merchandise and whatever else. The only way their salaries will go down if people stop watching sports.

3. Consolidated Private Monopoly (NO Real Competition)

The NFL, MLB, NBA, and NHL have no real competitors except themselves. The NFL and the MLB compete but not directly because they are complement goods rather than substitute goods. There is no other football league that directly competes with the NFL. So, the NFL has a complete monopoly and they can manipulate the market and how they see fit, and charge whatever prices because more than likely, sports entertainment probably an inelastic good. Even amidst the recession, some 24 teams raised their ticket prices while the other 8 made no changes. Consumers are not real sensitive to price changes. People are willing to pay heavy money to see a sporting event.