This season, J. D. Drew replaced Trot Nixon in RF for the Sox. Trot was a beloved player in Boston, and one of my personal favorites, so the convergence of Drew slumping and Trot coming back to Fenway have a lot of people yearning for the good old days. There are a couple of things I'd like to point out.
The Big Myth: J. D. Drew is fragile.
Here's how Trot and Drew stack up in terms of games played over the last three seasons:
Trot - 48 G
Drew - 145 G
Trot - 124 G
Drew - 72 G
Trot - 114 G
Drew - 146 G
Trot - 286 G
Drew - 363 G
If we go back and look at how many games they've played per season over their careers, Trot averages 121 games per season, Drew averages 118 games per season. So they've both missed significant playing time. However, keep in mind that two of the major injuries Drew has sustained in his career were the result of getting hit by pitches (2001 and 2005). He does have his share of nagging injuries that probably limit him to be a 140 game player but in my opinion, he's probably less "injury prone" than Trot (who is by the way 2 years older than Drew). I realize that they are probably different types of players, and get their injuries in different ways. Drew suffers more from the daily grind, whereas Trot never saw an outfield wall that he didn't want to slam into. Still in the end, Drew is probably less of an injury risk going forward than Trot is.
In terms of production, Drew has been superior to Trot over their careers. Drew has a career OPS of 0.894, Trot has a career OPS of 0.840. In terms of career wins over replacement level (which includes defense) Drew has been worth 48 wins, Trot 42. The money could be argued over. There's little doubt that Drew is overpaid, but given the other contracts handed out this winter, it's not really as bad as it seems.
I guess I'd summarize the change this way. The Sox replaced one productive but injury prone RF with a younger, more productive and less injury prone RF for a bunch more money.