For Major League Soccer’s best American players, it doesn’t pay to stay in U.S.

Somewhere along the line, Major League Soccer will have expanded into all the cities it wants to inhabit, built all the stadiums it wants to build, and signed all the designated players it wants to sign.

Perhaps then the league will give some serious attention to the upper-echelon American players in its fold, players such as Jonathan Bornstein.

If ever there was a case of MLS succeeding on one front while simultaneously failing on another, Bornstein is that example.

In only a few weeks, the 25-year-old Chivas USA defender’s MLS career will come to an end. After five seasons in the league, Bornstein is packing his bags and moving to Monterrey, Mexico.

Trading up from Goats to Tigers would seem to be a good move for the U.S. national team player, and the unanimous belief among his teammates and coaches is that Bornstein will do well when he joins the Tigres of Universidad Autonoma de Nuevo Leon on a four-year contract.

“He had other opportunities, but he feels that Mexico is the place where he wants to go and I think he will succeed,” Chivas USA Coach Martin Vasquez said. “Every game there’s a lot of pressure . . . but I think he will respond.”

When he moves to Mexico in January, Bornstein will become the latest in an endless stream of American players who have “graduated” from MLS to a more challenging, more rigorous, more lucrative league.

Once he departs, of the 23 players who were on the 2010 World Cup roster for the U.S., only three will be playing their professional soccer in this country — the Galaxy duo of Landon Donovan and Edson Buddle and Real Salt Lake’s Robbie Findley. Everyone else is in either Europe or Mexico.

That is not a knock on MLS. It’s no different in Argentina, Brazil, or anywhere else where the local leagues serve as steppingstones to higher competition.

The best players automatically gravitate to the best teams in the best leagues. It’s the natural order of things.

But sooner or later MLS is going to have to find a way to hold on to players such as Bornstein, and that comes down to money. Paying the starting left back for the U.S World Cup team $100,000 a year, as Chivas USA does with Bornstein, is just not going to cut it. He will earn four times that much playing for Tigres.

“Unfortunately, that’s where we still need to be able to compete in this league, financially, so that we’re keeping guys like that,” said Donovan, who makes $2-million a year in MLS, more than four times the salary of any other American in the league.

“It’s a shame for this league that we lose a guy like that, but we can’t compete yet.”

According to Shawn Hunter, Chivas USA’s president and chief executive, the club did everything it could to keep Bornstein.

“We very much wanted to keep Jonny,” Hunter said. “We offered him a new contract a little over a year ago and again going into the World Cup, but based on MLS rules and the [salary] cap, we couldn’t match Mexico.

“So I’m happy for him on one front because he deserves a new opportunity and a bigger payday, but we’re going to miss him.”

Chivas USA could have kept Bornstein by making him a designated player, like Donovan or David Beckham or Thierry Henry or Rafael Marquez or any of the other designated players in the league whose salaries count only partially against the cap.

But those players, MLS argues, put fans in the stands and sell merchandise, over and above contributing on the field. American players, with the possible exception of Donovan, do not do that. Not yet, anyway.

So the Americans head abroad.

“The way he plays, he can play anywhere,” Donovan said of Bornstein, formerly of Los Alamitos High and UCLA. “He likes it here, but he wants a new challenge.

“It’s going to be different, that’s for sure, than playing here. The game’s a little slower there, the tempo is slower. There’s different weather, heat, altitude, that kind of stuff, but I think he’ll adjust just fine.”

Said Vasquez: “He’s got the football, he’s got the mentality and, after playing in a World Cup, he’s got the experience.”

The bottom line for Bernstein, however, was the bottom line. He rejected offers from European clubs to join Tigres.

“That was a big factor in the decision-making process,” Bornstein, 25, said of the salary he is guaranteed for the next four years. “I had to think about the future. You can only play soccer for so long.”