Jayson Werth, above, is the latest high-profile Scott Boras client to sign on with the Nationals, joining Stephen Strasburg and Bryce Harper. (John McDonnell/THE WASHINGTON POST)

Agent Scott Boras’s partnership agreement with the Washington Nationals is unwritten.

He has no official title or specified role with the franchise. You won’t find office space set aside for Boras at Nationals Park.

What Boras does have — and what makes him a key player in the Nationals’ future — is a client roster that includes star starter Stephen Strasburg, right fielder Jayson Werth and top prospect Bryce Harper. Boras could have significant influence over the Nationals for many years because of their huge investment in Strasburg, Werth and Harper, and that’s not necessarily a bad thing.

Many of you probably read the previous sentence and laughed because of Boras’s reputation within Major League Baseball management.

Baseball officials, particularly many in the commissioner’s office and those who operate small-market franchises, blame Boras for much of the game’s dizzying contract boom since the 1990s. It seems Boras has almost single-handedly tilted the arbitration process and the amateur draft in favor of players because of his innovative strategies.

No doubt, Boras is an advocate for his clients and, in extension, all players. He’s an aggressive negotiator whose results often produce criticism.

But I know about another side of Boras. I’ve seen his full-service approach in helping his clients maximize their performance, which is rare among agents.

“The game has given me everything I have, and I want to do what’s right by it,” Boras said in a recent interview.

“The best contribution that myself and my company can make is to represent players and advise them, to help them condition themselves at optimal levels and help them play the game at optimal levels. To help them execute their contracts at the highest levels so that the fans remain in baseball and they have continued interest.”

Way back in the late ’90s, Boras was deeply involved with the Los Angeles Dodgers because of his prominent clients on their roster. Management embraced Boras and sought his counsel, believing he could assist them in achieving their goals.

Boras repeatedly helped the Dodgers resolve difficult situations with several of their best players. He prevented small internal issues from becoming big problems.

Other organizations also have privately leaned on Boras. During his more than 30 years in baseball, Boras has been encouraged to intervene with players. One general manager I know once asked Boras to reach out to a player who wasn’t one of his clients.

Boras negotiated a draft-record $15.1 million contract for Strasburg. He persuaded the Nationals to give Werth a seven-year, $126 million contract — the biggest in franchise history — that includes a complete no-trade clause. At 17, Harper was guaranteed $9.9 million.

All three are highly motivated players who, by all accounts, are determined to achieve because of their passion for baseball. It would be naive, however, to assume no hiccups will occur in their time with the Nationals.

Also, if things go as expected, Strasburg, Werth and Harper will account for an increasingly bigger portion of Washington’s payroll. The Nationals will have to deal with Boras, so having a solid professional relationship with him makes sense.

Third baseman Ryan Zimmerman, whom Boras does not represent, arguably is as important to the Nationals’ long-term strategy as any player in the organization. Reaching a multiyear agreement with Zimmerman before he can become a free agent after the 2013 season should be General Manager Mike Rizzo’s top priority.

Collectively, though, Strasburg, Werth and Harper give Boras a lot of leverage. Boras describes Strasburg, who might miss the entire 2011 season after undergoing Tommy John surgery, and Harper as “the best back-to-back draft picks in the No. 1 slot I’ve ever seen a team have in my 32 years of doing this.”

In addition, Boras also represents starting catcher Ivan Rodriguez. Danny Espinosa could start at second, and Rick Ankiel may win the center field competition, meaning Boras could have four clients in Washington’s everyday lineup.

The Nationals were criticized throughout baseball for overpaying for Werth, and the team formerly was opposed to no-trade clauses. But Werth fit nicely into Rizzo’s defensive-minded plan, and it’s a good thing the ownership group headed by the Lerner family supports the general manager’s vision.

That’s another thing about Boras: He’s one of professional sport’s all-time best pitchmen in meetings with owners.

No matter how much Rizzo believed in Werth, the move doesn’t happen unless the Lerners believed similarly. Obviously, Rizzo had an ally in Boras.

Team executives usually bristle at the suggestion agents play a part in their decisions. They cite scouting reports, analysis and their professional instincts in what they do — not the input of agents.

Owners want to know about the mental makeup of the people seeking their money. Boras provides personal insight into players raw data alone can’t reveal.

Rizzo is an inexperienced general manager, and the Nationals have struggled under the Lerners. It would appear the potential exists for Boras, as good as it gets in his field, to advance his agenda at the expense of the Nationals.

With so many of his clients on the team, however, Boras and the Nationals, to a certain degree, are in this together. Everyone wins if Boras’s clients succeed individually while helping the Nationals become a contender.

If Rizzo’s plan fails, then they’ll be linked in that, too. Either way, Boras definitely is in the mix with the Nationals.

“We look at ourselves as being in partnership with all the teams,” Boras said.

Albeit some a lot more than others.