The third baseman, who was the Cubs' No. 1 pick in the 2007 First-Year Player Draft, quickly learned that being a professional ballplayer requires a lot more work.
"It's been seven-, eight-hour days -- it depends on how long the game goes," said Vitters, during a brief break earlier this month at the Cubs' Minor League facility in Mesa, Ariz. "Sometimes it's longer than that."
There isn't much time to hit the weight room, and if he tries to do it after a game, it's tough because guys are worn out from the day's activities.
Welcome to the real world of big league baseball.
The Cubs don't doubt Vitters will make the adjustment. Nearly every player goes through the adjustment when baseball becomes a full-time commitment.
"This is what I thought it would be," Vitters said. "It's even more fun than I thought it would be. I'd heard it's a lot of hard work, and it is, but at least I'm having fun doing it.
"The camaraderie of the players is good, I like all the coaches, and I love playing the game, so it's real fun."
Vitters, 18, was the third player taken overall in the Draft after hitting .390 in 24 games his senior season with nine homers, six doubles, three triples, and 29 RBIs. He wasn't able to duplicate those numbers in his brief Minor League experience. Vitters played seven games for the Arizona Rookie League team, and was 2-for-30, and went 4-for-21 in seven games for Boise.
"It was fun playing in front of a pretty sufficient amount of fans [in Boise] -- we had 3,000 to 4,000 every day," he said. "I was playing against a lot older players, and there was electricity in the air. It was a lot different then high school ball."
He was disappointed in his numbers, and the time at Fitch Park helped him feel good heading into the offseason.
"I've been able to get my swing going back the way it should be," he said.
Vitters will return home for the winter, and knows he has to use the time to get ready for Spring Training.
"I'll be working out three times more in the offseason than during the season," Vitters said. "There's definitely a lot of work involved in the offseason, too."
Ranked as the top position player out of high school by Baseball America, Vitters was named Gatorade Baseball Player of the Year in 2007. He watched the Cubs a lot after the Draft, and likes how Ryan Theriot plays, and how Aramis Ramirez hits.
"Hopefully, I'll be like one of those guys when I get older," he said.
As a first-round pick, Vitters is ready for the high expectations.
"There's definitely a little pressure involved being the first pick," he said. "I think sometimes I put a little too much pressure on myself, knowing I'm the first pick and I have to be the best guy, but I just have to go out there and play the way I know I can play."
What helped was that Vitters had some other first-round picks to talk to, like Tyler Colvin, the No. 1 selection in 2006 out of Clemson, who was at Fitch Park working on his hitting before joining Team USA.
"We've talked a little bit," Vitters said. "He's an older guy, so I'm sure he can handle [the pressure] well."
What keeps Vitters going is the fact that he's living his dream. He's wanted to be a ballplayer since he was 10.
"I've always wanted to be a professional baseball player, and I've never thought anything different," he said. "Ever since I can remember, I thought I'd be a baseball player. It's sweet that it actually came true."
AFL update: Cubs outfielder Sam Fuld climbed up the Arizona Fall League's hitting headboard and ranked third in the circuit with a .400 average through Thursday.
Fuld hit .486 (18-for-37) in 10 games from Oct. 24-Nov. 8, with six doubles, a triple, a home run and six RBIs for the Mesa Solar Sox. He had two hits in five consecutive games entering Mesa's showdown Friday with first-place Phoenix.
Third baseman Josh Lansford is also off to a hot start to November, batting .381 (8-for-21) with at least one hit in five of six games.
It's a sellout: Tickets to the annual Cubs Convention went on sale at 10 a.m. CT on Monday. Ten minutes later, all 2,000 were sold out.
The fan fest will be held Jan. 18-20, 2008, at the Hilton Chicago, 720 South Michigan Ave. The convention will run from 3-9 p.m. CT on Jan. 18; 9 a.m. to midnight on Jan. 19; and 9 a.m. to 1 p.m. on Jan. 20. Included with each pass is access to all autograph/photo sessions, question-and-answer sessions, as well as the memorabilia and vendor booths.