The line on this year’s free agency and trade market in baseball is that it is the weakest the sport has seen in years — thin in functional players and still thinner at the top. The Mets may end up bringing back adequate, uninspiring players such as catcher Paul LoDuca and second baseman Luis Castillo just because there are no credible alternatives. With no offense meant to Castillo, a market in which he is a comparative gem is hardly a market at all.

At least teams dreaming of improvement have players worth dreaming on. Weak as the market is, both the best player and the best pitcher in the game can be had. Alex Rodriguez is a free agent, and with Johan Santana coming into the last year of his contract, the Minnesota Twins will be compelled to at least listen seriously to offers. What’s more (if an ESPN report is correct), neither will even be the most attractive player available.

Recently, ESPN’s Peter Gammons reported that the Florida Marlins are telling other teams they’re willing to trade 24-year-old third baseman Miguel Cabrera. Everyone knows that Cabrera is one of the best young hitters in baseball, but his reputation isn’t equal to what he’s done. His performance so far in his career is, as seen below, completely indistinguishable from that of legendary outfielders Hank Aaron and Frank Robinson, even when you take run context into account. (Baseball in the 1950s was as high scoring as it is today.)

Unlike Aaron and Robinson, who were excellent outfielders, Cabrera is a disaster in the field. At what looks like at least 260 lbs., he just isn’t nimble enough to play a good third base. But this isn’t a real issue, as he’s hit .320 with power, while growing two new chins to go along with his original one. If a new team can motivate him to stay in better shape, that’s all to the good, but from Babe Ruth to David Ortiz, baseball has always had a place for the fat hitter. What really counts is that Cabrera — who can play left field and could presumably handle first base — is younger than David Wright, hits like Manny Ramirez, and won’t be a free agent until after the 2009 season.

Cabrera, who is arbitration eligible, will likely make between $25 and $30 million over the next two seasons. Rodriguez will cost more than that per year for a decade, and after the coming season, Santana could be earning nearly as much. What’s more, Cabrera will probably be the best of the three players over any time span you care to choose. Rodriguez hasn’t really been much better than Cabrera over the last four years and is eight years older; Santana is a pitcher and thus inherently an injury risk. You’d surely like to have any of these three on your team — but in five years, Cabrera will still be only 29.

The world champion Boston Red Sox seem like the best and perhaps likeliest destination for Cabrera. With third baseman Mike Lowell a free agent, they have a need. Also, Manny Ramirez is 35, a potential free agent, and in seeming decline. Cabrera could take over the spot in front of the Green Monster and hit behind David Ortiz in 2009, and anchor the Boston lineup next decade the way Ramirez did in this one.

Boston can certainly meet the asking price, as they did when they traded for ace Josh Beckett under similar circumstances two years ago. As it was then, the price will be high, because Florida doesn’t need to move the player; their payroll this year was just $31 million, probably less than their share of Internet and revenue sharing money. Boston, though, has more ready young talent than it can use: World Series heroes Jacoby Ellsbury and Jon Lester, prospects such as Jed Lowrie, and pitchers such as Clay Buchholz, a 23-year-old ace in the making who threw a no-hitter in his second major league start.

Difficult as it is to trade top young talent, sometimes it’s best to do so, especially when equally young talent is coming back. In the Beckett deal, the Sox lost Hanley Ramirez, now 23 and the best hitting shortstop in baseball. They still came out ahead. A second such deal wouldn’t necessarily have the same results, but the Red Sox wouldn’t be afraid to make it. What’s true for the Red Sox is true for the Yankees, who could also use a third baseman. It’s an uncustomary position for them, but they do have the young talent to match most any offer any other team makes. In the past, when the possibility of this sort of trade has come up, the Yankees have been in the position of a homeless man loudly insisting he was far too prudent to squander his savings on a Rolls Royce. Now, with the arrival of Phillip Hughes and Joba Chamberlain, they are more like an investor trying to decide whether his money would be safer in stocks or bonds.

It will almost certainly take a pitcher such as Buchholz, Chamberlain, Milwaukee’s Yovani Gallardo, or the Dodgers’ Clayton Kershaw (the type of pitcher who is usually completely unavailable) to land Cabrera. Some, or maybe even all of these teams, will certainly decline to get involved in the bidding and instead talk about building from within, believing in their young players, and thinking toward the future. That team may look prescient five years from now. But Miguel Cabrera is himself only 24 years old — a year older than Buchholz, and two years older than Chamberlain. This wouldn’t be trading the future for the past, or even the present. This would be a trade for the future.

tmarchman@nysun.com