Zimmerman spent three years at the University of Virginia working toward a degree in sociology. He is one of 12 Nationals who went to a four-year college. Of those 12, only Tuesday's starter, Ross Ohlendorf, went on to graduate.
Many don't get a chance to graduate before inking a professional contract. Some players sign with a Major League club after high school, while others spend a few years at a junior college or university before being drafted.
"College is tough, man," Zimmerman said. "It's just very time consuming, and I just wouldn't want to go through that right now. I feel like at a certain stage in life, you're ready to do that stuff. And then once you get past that, you're just done."
Zimmerman signed a six-year, $100 million extension last year and said there is a 1 percent chance that he'll finish his degree. But for others, the desire to graduate lingers.
Chad Tracy, Zimmerman's backup, is 32 credit hours shy of a degree in exercise science at East Carolina University. Stephen Strasburg has three classes left before he can graduate from San Diego State. And Craig Stammen, a business management major at the University of Dayton, is actively working to finish his degree.
"It's a goal of mine," Stammen said. "I know my mom would be proud of me if I finished my degree, and it's something for me to be proud of, too, because there's not many players in the Major Leagues that have actually finished their degree."
The timing and length of the Major League season make returning to school a challenge. The last month of the season overlaps with the start of the fall semester, and Spring Training prevents players from taking classes in the spring.
Ohlendorf, the team's only graduate, said he was lucky. After being drafted by the D-backs in 2004, he was able to return to Princeton University in the fall because the semester didn't start until mid-September. Ohlendorfmissed a few Minor League games to walk at graduation with his classmates in the spring, and he officially finished his coursework the following fall.
"I was able to go back right away," Ohlendorf said. "My friends were still there. I was still in a going-to-school mode. It just made sense. I think [for] other people, if their schedules had worked out for them to go to school, they might've gone back right away."
Strasburg was able to chip away at a public administration degree in the fall of 2010, when he was recovering from Tommy John surgery. The righty has only three major courses left on his schedule, but San Diego State prohibits students from taking major courses online or at another university. For that reason, Strasburg said that he will likely have to wait until after his career to finish his coursework.
"It's just up to the way the season works and school works," said Strasburg, who is 6-9 with a 3.00 ERA this season. "It's not really a priority of mine right now. I've got a lot of other things going on. But when the time comes, I would like to get that degree."
Tracy is in a similar position. While he has thought about finishing his degree, he won't go back to school until his baseball career has ended. Tracy and his wife, Katie, have contacted East Carolina with hopes that the veteran infielder could finish most of his remaining coursework online.
"I've lived most of my focus that I had in college, which was exercise and sports science," Tracy said. "I could write a paper on a few different surgeries and rehab programs and the day-to-day life of how it applies to a baseball player. So I would hope that that would carry some weight."
Stammen, who finished one semester after being drafted by the Nationals in 2005, has 15 credit hours remaining.
"I think if I get it done, I would have to take classes during the season at some point, somehow," Stammen said. "I don't know if I want to do that or not, but I've got a few people that want to work with me to get it done."
Tracy's greatest concern is what prevents many players from continuing their education after baseball. At 33, he doesn't want to spend any more time in a college lecture hall.
Ohlendorf has a different perspective. He said that taking a year away from school to play baseball gave him a new appreciation for his classes.
"I remember having a really good experience," Ohlendorf said. "I think a lot of it depends on whether you're in classes that interest you. And I think at this point, for guys that are going back, they probably have a better feel for what classes do interest them. So if they're able to have the flexibility with their requirements, it could be a good thing."
Ohlendorf has thought about going to business school or law school after his baseball career is over. Tracy might open a small business. Strasburg would like to finish his degree so that he can one day take over the baseball program at San Diego State.
Stammen just wants to make himself -- and his mother -- proud.
"It'd be nice to have that feather in my hat," Stammen said. "I'll figure it out somehow."