WEST PALM BEACH, Fla. - There is no way to adequately prepare in only two spring training starts for pitching in a high-level international competition at the end of the week. Tanner Roark knows this. He also knows he has done everything he can so far this spring to prepare himself as best he can for his next assignment: the powerhouse Dominican Republic in the World Baseball Classic.

“I feel like I’m well prepared,” the Nationals right-hander said. “Body feels good, arm feels good, mind feels good. I’m just going to go out there and do what I do and compete and do the best I can.”

Roark said this after tossing four scoreless innings against the Twins in front of a crowd of 4,588 at The Ballpark of the Palm Beaches. His next start will come Saturday night in front of a sellout crowd at Marlins Park when Team USA takes on the Dominicans, perhaps the highest-profile game of the first round of the WBC.

How exactly does one prepare to go from the non-stakes of spring training on March 5 to the high-stakes of international play on March 11?

“It’s definitely odd, for sure,” Roark said. “Going from, today’s crowd was pretty packed, and I don’t know what the capacity of the stadium is, but sold out Marlins Park is going to be pretty loud.”

Roark is one of five Nationals who have now left big league camp to participate in the WBC. He’s joined on Team USA by second baseman Daniel Murphy. Catcher Jhonatan Solano is playing for Colombia, while left-hander Oliver Pérez will pitch for Mexico. (Right-hander Rafael Martín is among the pool of eligible pitchers for Mexico and could leave camp should his home country advance past the first round.)

It’s not the most popular event among baseball people, who are more worried about injuries and other uncontrollable factors that could hurt major league teams’ chances during the season. But Roark and Murphy, in particular, jumped at the opportunity to play for Team USA.

“Really looking forward to playing with some of the best players in Major League Baseball,” said Murphy, who may start either at second base or as designated hitter. “Not only with them, but against them. The rest of the teams seem to be truly talented right now, so it should be a lot of fun. I never had the opportunity to wear red, white and blue, and represent my country.”

The Nationals can’t prevent a player from participating in the WBC, not unless there is a particular injury concern. (Max Scherzer, for example, pulled out of the tournament earlier this winter when he realized the stress fracture in his right ring finger wouldn’t be 100 percent healed in time. Roark wound up taking his place on the American roster.)

But manager Dusty Baker and his staff have been in touch with USA manager Jim Leyland and his staff, and there’s an understanding what needs to be done to make sure Roark and Murphy return from the tournament having still properly prepared for the regular season. Baker also trusts his players to approach matters in a responsible way.

“They’ve got an idea,” the manager said. “It’s not like they’re kids. And they realize the importance of the WBC, but they also realize the importance of the season in their careers and what it means to us to try to win. They’re led by Murph. Murph has got a heck of an idea what to do. ... So I’m not worried. I just told them to go and represent their countries well. I can’t tell you who I’m rooting for - that’s what I told them - but I want you to play well and represent yourself and your organization and your country.”

Murphy has his fair share of experience on the national stage, most notably his dominant run through the postseason and into the World Series with the Mets in 2015. Roark has pitched in the playoffs - he started Game 2 of the National League Division Series last fall - but the WBC could provide a new opportunity for the rest of the baseball world to appreciate how good the 30-year-old right-hander is and has been for the Nationals.

“We all know how Tanner is,” Murphy said. “He kind of, I don’t want to say lulls us to sleep, but he spoils us with how good he is consistently for 30 starts a year. Especially last year. So I’ll be excited to see what the rest of the industry thinks of him. I think it’s well-earned for him to get tapped on the shoulder for this, and I’m looking forward to him enjoying it.”

Roark had wide eyes talking about the upcoming experience this afternoon before departing West Palm Beach.

“I’m excited to meet all the guys,” he said. “I’ve never been a part of anything like this before. So getting the best of the best in the major leagues is pretty cool. I’ve never been a part of anything like that, so it’s a unique situation and I’m honored to be asked to play for the U.S.”