Whatever else it may be, baseball can be a straight-out racket. Tampa Bay Rays third baseman Evan Longoria, for instance, was first called up to the majors April 12. Six days later — having hit one home run in his career — Longoria signed a $17.5 million contract that could end up keeping him in Florida through 2016 for $44 million if the team exercises a series of options.

The scam here, of course, is in the team’s shrewd exploitation of baseball’s labor rules. For the first several years a player is in the majors, a team can pay him whatever they’d like, and even when he’s earned arbitration rights, he usually won’t earn anything more than a fraction of his market value until his walk year. A team thus has enormous leverage over a player under salary control. They can offer a blue-chip prospect, such as Longoria, a contract that is at the same time perfectly fair — setting him up for life and insuring him against injury or sudden decline — and a total farce. (Baseball Prospectus, for instance, conservatively projects that Longoria will be worth $105.5 million just through 2014.)

Using this leverage to sign a player during his first week in the majors (and obviously negotiations had been underway even before his debut) is just the logical extension of the trend toward buying out arbitration years that the Cleveland Indians started nearly two decades ago. Several other recent Rays moves are in the same line. Longoria’s deal followed on the January signing that will keep 26-year-old right-hander James Shields with Tampa Bay at least through 2011 and possibly through 2014; and an extension signed earlier this month will keep 24-year-old ace left-hander Scott Kazmir with them at least through 2011.

What’s more interesting than the first-place Rays locking up their core the same way that Cleveland and Oakland did in the past, though, is that the Longoria move is part of a much bigger trend. Certainly lots of attention has been paid to the staggering contracts young players have been signing lately, most notably Florida shortstop Hanley Ramirez’s six-year, $70 million deal. There’s nothing at all unusual about players too young to file for free agency signing big deals; stars such as David Wright, Jose Reyes, Robinson Cano, and Brandon Webb, among others, are under long-term deals with team options to buy out some of their free agent years. What’s less important than the money, though, is the service time of the players involved.

Just two years ago, Cleveland signed center fielder Grady Sizemore to a six-year, $23 million deal that was, at the time, the richest contract ever for a player with less than two years in the majors. Longoria is one of four players who have beaten that mark in recent months. Colorado shortstop Troy Tulowitzki signed for six years, $31 million; Arizona center fielder Chris Young signed for five years, $28 million, and Milwaukee left fielder Ryan Braun inked a deal for eight years, $45 million. When a smart but conservative organization such as Milwaukee is doubling the previous record, something is clearly going on.

These deals will have two major and related effects on baseball, ones that will probably disproportionately affect the New York teams, reliant as they’ve always been on signing top-rank stars on the open market. They won’t at all clear the free agency decks, as you might think they would. But they will make it even harder than it already is to build a great team around free agents, by making it even rarer than it already is that star players hit the market in their primes.

The first effect should be a mutually reinforcing tendency toward signing players to longer and longer deals at earlier stages of their careers. The reason for this is the quirky nature of salary arbitration, in which a player is compared to like players with like service time. Traditionally, this has led to something of an inflationary spiral — once one player gets a big arbitration award, he brings up the salaries of all the players behind him — but this year, the cream of an entire rookie class has been locked into certain salaries. The prospect of cashing in on inflated arbitration comparisons will thus be doing fewer players less good than it once did.

The second effect is that free agency classes will be older, as teams buy out more prime free agency years in exchange for not paying young stars the minimum salary. 2012, for instance, looks right now to be a potentially spectacular class — Kazmir, Prince Fielder, B.J. Upton, and Ryan Zimmerman could all hit the market at the prime ages of 27 and 28, with 29-year-olds Sizemore and Russell Martin also available. Assuming various options are exercised, though, the next two years after that will be drought-stricken for stars under 30. 2013 looks to have only a 29-year-old Brian McCann and a 25-year-old Justin Upton (potentially baseball’s second $200 million man), and 2014 only a 29-year-old Tulowitzki. Players such as Young and Ramirez will likely have played out the end of their absolute primes on contracts they signed this year.

Money will always win out when it comes to getting stars, but, as a look at either of the New York teams right now could show you, stars of a certain age aren’t always worth having if they come attached to a long-term deal. Even poor Longoria, dewy and new as he is now, won’t hit the market until he’s 30 and with his best years probably behind him if the Rays play him through all those option years. It almost isn’t fair.

tmarchman@nysun.com