While Olympic runner Marion Jones prepares to enter prison, New York Yankee pitcher Andy Pettitte is off to spring training.

There may be legal nuances that justify the disparate penalties in these two cases, but from a practical standpoint, the comparative treatment of these two athletes seems patently unfair.

Both Jones and Pettitte had the grace, in the face of compelling evidence against them, to admit that they had used performance-enhancing drugs, that it was a stupid thing to do and that they were sorry for the damage their actions had done to their sport and those close to them. The fact that they were willing to publicly come clean should earn them some respect, and perhaps some leniency, especially compared to those who continue to plead their innocence even in the face of overwhelming evidence to the contrary.

Pettitte’s use of human growth hormone was detailed in former U.S. Sen. George Mitchell’s report on illegal drug use in professional baseball. Although Baseball Commissioner Bud Selig reportedly hasn’t decided whether any punishments will be doled out as a result of the report, Mitchell urged Selig to bypass penalties because everyone involved in baseball should share the blame for “the steroids era.”

The same rationale easily could be applied to track and field athletes. Baseball is a team sport, while track and field is primarily an individual endeavor, but both were stained by the perception that athletes had to push the envelope and perhaps the legal limits in order to compete.

It seems likely that Pettitte’s confession and contrition will enable him to continue his career. Because it would be difficult to successfully and fairly prosecute all the ballplayers who used illegal drugs in the last 20 years, that may be appropriate. Like universities that self-report their violations, Pettitte may deserve a break.

But there seems to be little willingness to do the same for Jones. The mother of two is scheduled to surrender March 11 to serve a six-month sentence in a federal prison camp in Texas. Like many athletes currently under investigation, she repeatedly denied her guilt, thereby digging herself in deeper. Like Pettitte, she eventually came clean, but not until after she lied to federal prosecutors about her illegal drug use. She forfeited five Olympic medals for her crime and was sentenced to prison.

Many observers probably think Jones deserves that punishment, but if she does, so does every other swaggering athlete who uses an illegal substance and lies about it. The reality is that most Americans are far less interested in seeing athletes punished than in seeing amateur and professional athletics cleaned up.

Instead of belated punishments, what’s needed is a serious effort – through vigorous testing and a change in the culture of winning at any cost – to keep drugs out of sports in the first place.

Spectators need to believe that the athletes they are watching are competing honestly and that no one is gaining an unfair advantage through substance use. If athletes and all the people who make money off them want to preserve their audience, they would be smart to waste no time in restoring that basic level of integrity to their sports.