Representing his country was a dream Orioles center fielder Adam Jones had since he was a teenager growing up in San Diego.

Twice while he was in high school, he tried out for his Team USA age-group squad and didn't make it.

But now, the 27-year-old Jones will have his chance, playing for the United States in the third World Baseball Classic, which begins Tuesday.

"I got cut from Team USA tryouts when I was 15 and 16," Jones said. "I just wasn't good enough. They took other players, and that was fuel to me to get better. Even at 16, I realized that you've got to get better. Last one standing."

The lesson Jones learned was simple: Keep working, don't take a day off, and like a saying he often uses on Twitter — stay hungry.

"Now I get to play when it matters," Jones said. "[I'm] excited that I get to wear my country on my chest. No prouder moment as an American."

Jones played his last game before leaving Orioles spring training in Friday's win, 6-5, over the Pittsburgh Pirates in the Grapefruit League before departing for Arizona on Sunday morning to begin training with Team USA, which opens pool play March 8 against Mexico.

For Jones, not making Team USA as a teenager served as motivation that he uses to this day. He has used doubters to drive him to become one of the best young players in the game.

"I've always been the underdog my entire life," Jones said. "I missed a couple Team USAs, and I worked my [butt] off and I wasn't good enough, so it was completely understandable. There were guys who were better than me at the time.

"I've been told I wasn't going to hit myself past [Single-A]," Jones added. "I remember I got to Triple-A at 20, I saw one of the scouts who said something like that, and I said 'Thank you, buddy, you just threw fuel on my fire.' That's all it is. I'm not here to prove nobody wrong. I'm here to prove myself right."

Now Jones is a two-time All-Star, a two-time Gold Glove winner and the face of the Orioles franchise, signed a six-year, $85.5-million contract extension last season that keeps him in Baltimore through 2018.

Jones said the decision to play wasn't a difficult one. But it is still tough leaving Orioles camp.

"[You] get to play for your country," Jones said. "I'm going to miss these guys here, but they understand the opportunity that I have, and I'm pumped to be able to play for Team USA."

This spring, Orioles manager Buck Showalter has given Jones as many at-bats as possible to get him ready for the WBC. In the team's intrasquad scrimmages prior to the start of the Grapefruit League season, Showalter batted Jones leadoff to get him more at-bats.

But Showalter doesn't hide his concern about the WBC. Every manager has the same worry about his key players getting injured.

Two Orioles pitchers — Miguel Gonzalez (Mexico) and Jim Johnson (United States) — declined invitations to participate in the tournament, saying that staying in major-league camp would better help them prepare for the season.

Relief pitcher Pedro Strop (Dominican Republic) and Jones, as well as top position player prospect Jonathan Schoop (Netherlands) are playing in the event. Several Orioles minor leaguers, including catcher Chris Robinson (Canada), catcher Allan de San Miguel (Australia), pitcher Jonatan Isenia (Netherlands), pitcher Rafael Moreno (Brazil) and outfielder Tim Smith (Canada) are also participating.

"You see these players as precious commodities of the Orioles and of the city of Baltimore," Showalter said. "You just hope they return in the same condition they left."

Jones is coming off a season in which he played all 162 games, overcoming injuries to both wrists that nagged him throughout the season.