I know the potential of a Cliff Lee trade has been discussed quite a bit (there's a whole megathread for it). The consensus wisdom among the chattering classes seems to be that New York is his ultimate destination. Polls on MLB Traderumors reflect this (Boston wasn't even a named option). Nevertheless, at this point in the season, Lee would be a much better acquisition for the Red Sox than he is for the Yankees, or the Mets.
Lee has had an interesting career trajectory. In his four seasons prior to 2008, he alternated good and bad years, culminating in a disastrous 2007, where he lost time to injury, pitched only 97 innings, and ended the season with a 6.29 ERA and without appearing on the Indians' playoff team. But over the past three years, he's put up some astonishing numbers: a 2.89 ERA, with 7.1 Ks and 1.4 walks per 9 innings.
With those numbers, any team in baseball would be able to find a space for him. However, the Yankees are one of the teams that least need pitching help. They are currently 3rd in the AL in ERA (3.80), with spectacular starts from Andy Pettitte (2.46 ERA) and Phil Hughes (2.71), as well as good work from Burnett and Sabathia; even Javier Vazquez has been pitching better of late. With New York's stock of young players already depleted by the trades for Vasquez and Curtis Granderson, and pitching decidedly not a problem, it doesn't make much sense for them to trade for Lee.
The Mets have a shakier rotation, and could readily replace, say, Olvier Perez and his 6.28 ERA with Lee. Perez and former ace John Maine are both on the DL and having bad seasons thus far, although Maine should be much better if he returns healthy. However, the Metropolitans would be better served by improving their offense: they are 5th in the NL in ERA (3.71), but 9th in runs scored.
Which brings us to Boston. It's pretty clear this is not a bridge year: our opening day payroll jumped from $121 million last year to $168 million for 2010 (source). You don't commit that much cash to a team just to build for 2011 or 2012. When they aim for the playoffs, the Sox usually make a mid-season deal to improve the team, from blockbusters like the 2004 acquisitions and 2008's Jason Bay trade to lesser deals like grabbing Paul Byrd. And the Red Sox need some big-time help with their pitching: their 4.35 team ERA is 9th in the AL. This despite having the 3rd best defense in the league, according to UZR (behind the Rays and Twins). If not for their league-leading offense, Boston wouldn't even be in contention right now. A pitcher like Lee could do much to change our pitching's fortunes.
There are some logistical questions to a trade. Can Boston absorb Lee's salary? Yes; a pro-rated $9 million wouldn't be hard, especially if they moved Lowell elsewhere. And after Theo's Steinbrenneresque Orgy of Spending in the offseason, money doesn't seem to be much of an issue philosophically. Does Boston have the prospects to deal? Yes. Casey Kelly straight up would probably get it done, but there are plenty of other names in our highly-ranked system.
In previous years, I would have said there was no way that Cliff Lee would be walking into the Sox clubhouse. Trading young talent for a guy on the doorstep of free agency is generally a poor long-term move. But with our vaunted rotation in shambles (Beckett is MIA, Lackey is lackluster), Lee could be an enormous help.
Cliff Lee to Boston makes sense on so many levels. So why don't I like this idea? First, we still have 4 ace-like starters, and that really ought to be enough. If Lackey and Beckett return to form, and Buchholz and Lester stay strong, we will have traded good prospects for a luxury. Second, Lee doesn't help us much in the long-term. If the Sox extend him, they are locked in at huge money to a 32-year-old player who could easily start reverting to his pre-2008 form. If they don't extend him, we've given up talent for half a year of a top player. Third, such a trade reeks of Yankeeism (i.e. OH NOES OUR ACES ARE BAD LETZ GET ANOTHR ACE SO JETER CAN HAZ ANOTHR RING!!!!).
With tough competition from Tampa, New York, and even Toronto, Theo may well decide that Lee is needed to make the playoffs, regardless of the price or consequences. Look for Boston to be connected to the Lee speculation more frequently in the coming weeks.