Three months ago, anyone claiming that a four-game Red Sox-Yankees set, culminating in a nationally televised Joba Chamberlain start, would be the second-most interesting series in the American League East this week would rightly have been written off as a madman. As July opens, though, the attention of the baseball world is fixed on St. Petersburg, Fla., where the defending world champions are attempting to wrest the division lead from the Tampa Bay Rays.

As much attention as these two series are getting, though — and they more than deserve it, especially with the Rays defending first place with top starters Scott Kazmir, James Shields, and Matt Garza — the frightening thing, at least for those accustomed to enjoying the long-established order in the East, is how much they portend for the future. The significance of the week is less that Boston and Tampa Bay are warring for first while the Yankees are trying to edge their way in, but that there’s a good chance that this is how things will be for the next several years.

One figure should give a good idea of the reason why: $159 million. That’s what the Rays will have to pay to keep left fielder Carl Crawford and first baseman Carlos Pena through 2010, Kazmir through 2012, Shields through 2014, and third baseman Evan Longoria through 2016. It’s about half what the Yankees owe Alex Rodriguez, and it will carry all of these players through their primes. Kazmir, 24, may be the best pitcher in the league. Longoria, 22, is hitting as well as David Wright and should develop in the same line. The rest are All-Star-caliber talents. And the Rays owe none of them anything remotely like what they’re worth.

What’s still more impressive is what’s behind them. Center fielder B.J. Upton may be the team’s best player, and he’s years from free agency, as are Garza, catcher Dioner Navarro, and starters Edwin Jackson and Andy Sonnanstine, who have pitched a combined 197.2 innings with a 4.46 ERA. All of these players are between 23 and 25; between them they’re making about $2 million, and they won’t be making much more next year. And in the minors, the team has three potential frontline starters — David Price, Jake McGee, and Wade Davis — as well as power-hitting shortstop Reid Brignac and Tim Beckham, another shortstop and the first overall pick in this year’s draft.

Good as the Rays have been — and they could improve, as no one is seriously overperforming; Crawford and Pena are hitting at about the league average, while shortstop Jason Bartlett has yet to raise either his on base or slugging average above .300 — they’re going to get a lot better, starting next year. Their young players are going to move closer to their absolute primes, and their low payroll and embarrassment of young pitching will allow them to trade for, or even sign, anything they need. What we’re seeing this year is less a Cinderella story than the emergence, a year early, of a team in the vein of the 1990s Indians or the Moneyball A’s.

The Yankees would, in any case, have a hard time competing with this, not because of any failing on their part, but just because they are, with noted exceptions such as Chamberlain, old. Derek Jeter, Bobby Abreu, Johnny Damon, and Hideki Matsui are all 34; Andy Pettitte and Jorge Posada are 36; Jason Giambi is 37; Mariano Rivera is 38, and Mike Mussina is 39. Most of them are making more than the Rays’ three highest-paid players combined, something fans like to think doesn’t count but is very much on display whenever a call is made to the bullpen. But staying in the running against not just the Rays but the Red Sox, who are run much as the Yankees are but more efficiently and with more players in their primes, is going to be extraordinarily difficult.

In all, this poses a real question for the Yankees, one this week’s games should go some length toward answering: How hard a run should they make this year? They’re very much in the race, and however good the Rays may look right now, they haven’t felt the pressure of a real playoff run before. There’s also an argument to be made that this could be the Yankees’ best shot for a while; as their old-timers leave or collapse over the next two years, the Red Sox should keep clipping along at their usual pace while the Rays fill holes with top-rated prospects making the league minimum and watch players such as Upton bloom into their full potential.

For all that, though, there is a scenario where Phil Hughes and Ian Kennedy blossom next year, where Robinson Cano and Melky Cabrera fulfill all their potential while Chamberlain wins 20 games and minor leaguers Austin Jackson and Jose Tabata spring into the majors fully formed as if from Athena’s brow, and where the Yankees can match the Rays and the Red Sox nearly young player for young player while bludgeoning them with their massive payroll advantage. However likely this is, going for it all this year would almost certainly mean risking it — and with it, the team’s chances of competing for the next several years in a division that looks even more brutal now than it did three months ago.

tmarchman@nysun.com