Nationals right fielder Jayson Werth: “My whole life has always been, you got to kind of get to know me. But usually first impressions are not my strong suit.”: (John McDonnell/THE WASHINGTON POST)

Around the Washington Nationals, there is a commonly accepted notion about Jayson Werth: He will meet people with skepticism before he trusts them, and he will open up over time, on his terms only. Werth insists this is backward. It takes others time to come to know him, he says, and then they feel comfortable. The perception of him evolves and he remains the same, not the other way around.

“I’ve never been one to make a good first impression,” Werth said Friday morning, leaning on a black baseball bat not far from the batting cage at Space Coast Stadium. “My whole life has always been, you got to kind of get to know me. But usually first impressions are not my strong suit.”

When the Nationals signed Werth in December 2010 to a seven-year, $126 million contract, they trumpeted his ability to change a franchise not only with his play, but with his off-field contributions. Two years later, the vision has come to bear, far beyond the usual buzzwords about “leadership” and “culture.”

One week away from his third opening day in Washington, Werth’s influence has spread through every phase of the Nationals’ operation, from the training room to the front office, from rookies in their first spring training to ownership.

He tells teammates when they need to run their last sprint. He tells security guards when they need an extra body in the bleachers. He tells the general manager when the training room needs new equipment. He can bounce between roles — clubhouse enforcer, protector of teammates, emissary to management.

The Post Sports Live crew discusses whether Stephen Strasburg will throw more than 100 pitches in at least one-third of his starts this season. In his first year back after Tommy John surgery, he topped 100 pitches in only five of his 28 starts. (Post Sports Live/The Washington Post)

“He doesn’t just straight accept things,” reliever Drew Storen said. “It’s not, ‘Oh, whatever.’ He gets things done. If something is not right, he’s going to fix it.”

If you think that is an empty cliche, you haven’t met the blood nutritionist or used the isokinetic activation device. Werth pushed the Nationals to improve how they feed, train and maintain the health of their players. They listened, spent more money and made upgrades.

“He’s really a forward-thinking person,” said Mike Rizzo, the general manager. “He’s brought a lot of ideas to the ballclub. And that really was what we were looking for from him.”

‘I’m just kind of being myself’

Werth is not the outward face of the franchise, an unofficial honorific that still clings to Ryan Zimmerman. Nor is he their best player, the title Bryce Harper will soon own if he does not already. But he is the Nationals’ oldest (34 in May), highest-paid ($18 million per year) and most experienced (1,006 career games) player.

“Sometimes it seems like he’s been here 12 seasons,” Zimmerman said. “In a good way.”

The stature serves as currency, but that is not how Werth views his place on the team.

“I don’t really look at it as being a leader,” Werth said. “I’ve never really been a follower. I’m just kind of being myself. In 2011, I think being myself was probably a little too much at times. Guys didn’t know me, didn’t know how to take me. The perception was totally different. People being around me enough to understand how to take me, that’s kind of taken care of itself. I try to just be myself. But sometimes, that’s not easy to do, either.”

Zimmerman, the other Nationals player with the status to take complaints or requests to management, had only known one experience. To him, everything the Nationals did was the way things happened in the major leagues. And, anyway, “that’s really not me,” Zimmerman said. “Sometimes, it takes someone like Jayson that’s a little bit more outgoing that says, ‘This has got to be different.’ ”

Werth had played for a World Series winner in Philadelphia and had been around professional baseball for more than a decade. He could recognize what the Nationals lacked; he knew better. And, with a restless fervor, he would not abide shortcomings.

“I came here for a reason,” Werth said. “I was told this place was going to be right. So when you see things that aren’t right, you speak up. If you don’t speak up, you just kind of accept it. I wouldn’t say I’m the most accepting person in the world. I’d rather try to get things right, nip it in the bud right away and take care of it so we can move forward.”

And so Werth started speaking up. “Probably not very tactfully,” he said. “But the squeaky wheel gets the oil.”

During the 2011 season, he pulled Rizzo aside after games or during batting practice. After the season, Werth invited Rizzo to his home in suburban Virginia. Rizzo accepted.

“He comes up to me all the time,” Rizzo said. “He’ll make suggestions. I’ll tell him sometimes he’s full of [it]. Sometimes I’ll say, ‘That’s a good idea. Let me think about it.’ ”

‘Man, he was kind of right’

The numerous ideas that stuck became tangible symbols of Werth’s off-field impact. In the clubhouse kitchen, no longer does a cook make whatever players ask for. A chef trained in nutrition informs players how much sodium, fat or Vitamin A they should be eating.

“We’ve gone from probably the worst food in the league to the best food,” Werth said. “It’s more about nutrition. If you owned a racehorse, on the way to the race, would you stop at a fast-food restaurant and expect that horse to win?”

Werth advocated for better equipment in the weight room, and Rizzo took the requests to ownership. The Lerners bought both a single and double isokinetic activation device for $4,500. Position players use the single to build core strength. Pitchers use the double to strengthen their shoulders, one of the most important precautionary measures they can take.

The Nationals also added a long press, the barbell system Olympic weightlifters use, for $600 at Werth’s urging. They already had kettle bells weighing 55, 65 and 75 pounds. Werth persuaded them to purchase a 100-pound kettle bell for $500.

“At the beginning, people are like, ‘God, this guy,’ ” Zimmerman said. “At the end, they’re like, ‘Man, he was kind of right.’ . . . It’s like the guy at work that complains about the copier. Nobody wants to go to the boss and complain. But then once someone does, everyone is a lot happier.”

Last year, the Nationals’ front office spearheaded a four-month, in-depth analysis of their medical needs, comparing their processes to other teams and identifying areas of weakness. Werth played an instrumental role, suggesting alternative therapies — the Nationals obtained the services an acupuncturist at his urging — and recommending nontraditional specialists.

Werth told the Nationals about Robert Pastore, who describes himself on his Web site as a “biochemical detective.” Pastore analyzes a patient’s blood to determine what nutrients a person has in abundance or lacks. Based on his findings, he prescribes a diet intended to correct those imbalances and, ultimately, prevent injury.

Rizzo paid $2,500 out of his own pocket to act as the guinea pig. A nurse came to his office, collected five vials of blood and sent them to Pastore’s office in New York. “Pretty good,” Rizzo said of his results. Now a player can arrange his own test through the Nationals.

Werth also introduced the Nationals to a chiropractor, Keith Pyne, whose clinic specializes in neuromuscular structural integration.

Newcomer Dan Haren visited Pyne before spring training, and he said the consultation made his hip and back feel freer.

“We did a lot of work in the front office on, what’s the new way of competing and beating teams?” Rizzo said. “We came up with a strategy that we think helps and gives us a little edge and keeps people on the field.”

‘I’m here to win’

Teammates say Werth’s demeanor has not wavered, that he was the same person when he struggled in 2011 as when he became one of league’s toughest outs down the stretch last year. They can also see why someone with his attention to detail would have been tested by the transition to a new team.

“Watching him and seeing how meticulous he is with his routine, almost to a fault sometimes, where if something doesn’t go right, he’s like, ‘Aaargh!’ ” Zimmerman said. “That’s fine. I know I keep saying consistency, but that’s what I think of when I think of him.”

As Werth settled in and moved his family to town, his play improved. The surge culminated with perhaps the greatest at-bat in Washington’s baseball history, the 13-pitch marathon he ended with a walk-off homer in Game 4 of the National League Division Series against the St. Louis Cardinals.

“He kind of has that ‘I don’t care’ attitude,” center fielder Denard Span said. “Like, ‘We’re going to go out there and we’re going to be loose, and we’re going to have fun, and we’re going to kick some butt.’ ”

Last spring, Werth slipped a paper nameplate reading “NAMATH 12” above Harper’s locker, a reference to the 20-year-old outfielder saying in an interview he wanted to be like Joe Namath. This year, minor league infielder Zach Walters walked past Werth in the clubhouse with neon green shoelaces in his sneakers. “Nice laces,” Werth said. “Change them.” Walters did.

“He’s not going to come in and greet you with open arms, because you have to earn your keep,” said Tyler Moore, a rookie last season. “You kind of grow into it.”

The Nationals know Werth now, regardless of how it happened. During the conversation Friday morning by the batting cage, he considered the question of whether he changes to let people in, or if it’s that people warm to him. But only for a moment.

“I don’t know,” Werth said. “Nor do I care, really. I’m here to win. I’m here to play baseball. I’m not here to make friends. I’m not here to be your pal. I’m here to win.”