Another one of my Baseball Prospectus pieces syndicated on ESPN Insider, this one on trying to quantify what the absences of Alex Rodriguez and other stars would cost their teams in terms of runs and wins:

When the news on Alex Rodriguez’s hip injury broke last week, the Baseball Prospectus crew brainstormed a few possible solutions for the Yankees. Unsurprisingly, we reached an inevitable conclusion: he’s virtually irreplaceable, at least when it comes to finding a player under team control who could offset the expected loss of production.

Bound for surgery, Rodriguez is projected to miss six to nine weeks. Barring a trade, his most likely in-house replacement is 33-year-old journeyman Cody Ransom, whose solid .251/.348/.432 line over the course of 214 major league plate appearances spread across six seasons is dwarfed by a lengthy, significantly less impressive minor league track record which drags down his PECOTA weighted mean projection to a brutal .216/.293/.386 line and a -0.164 Marginal Lineup Value rate, the number of runs per game he would contribute (or cost) to a lineup of otherwise average offensive performers. By comparison, Rodriguez is forecast for 0.174 MLVr, a difference of 0.338 runs per game. That’s 10 runs—or roughly one additional win—for every 29.6 games, or 54.8 runs over the course of 162 games.

As staggering as losing roughly one more game per month in the standings might be to the Yankees, at least 10 other stars’ losses would cost their teams even more—as many as 75 runs on the offensive side—due to a combination of higher MLVr projections and/or lousier backups. In reality, the extended absences of these players would likely trigger trades for better replacements to stop the hemorrhaging, but for this exercise, the pool is restricted to players under team control, and we’ll pay only lip service to defense.

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3. Ryan Braun, Brewers LF (0.231 MLVr, 0.434 above backup): While Braun’s overall 2008 line couldn’t quite equal his 2007 numbers, the move from third base to left field saved 30 runs according to our defensive numbers. His MLVr ranks ninth among our PECOTA projections and is exacerbated by the Brewers’ lack of a suitable backup. Tony Gwynn Jr. (-0.203) and Chris Duffy (-0.239) carry weak sticks even for center fielders, and it’s a stretch to assume that Trot Nixon (0.010) will suffice given that he played in just 11 major league games last year. Former top prospect Brad Nelson (-0.083), a first baseman who’s taken up the outfield corners in an attempt to win a reserve job, would bump Braun out of the top 10 if he can handle the move to the pasture.

4. Albert Pujols, Cardinals 1B (0.456 MLVr, 0.398 above backup): Pujols’ MLVr tops our projections, hardly surprising given that he’s ranked either first or second in that category in five of the past six seasons. What prevents him from topping this list is the presence of the serviceable Chris Duncan (0.058), who’s played 43 games at first over the past three years and who appears to be recovered from last year’s neck problems. Once you figure in Pujols’ prowess with the leather and Duncan’s lack of same, however, this could well reclaim the top spot here.

5. Manny Ramirez, Dodgers LF (0.245 MLVr, 0.369 above backup): Last week’s signing averts the grim specter of the Dodgers starting the season with a slap-hitting $44 million left fielder (Juan Pierre and his -0.124 MLVr), instead of a power-hitting $45 million model. Skipper Joe Torre might have eventually stumbled onto a more productive solution by playing Blake DeWitt (-0.061) at third base and moving Casey Blake to left, but then again, it took the skipper over four months to give up on Pierre and Andruw Jones last year. Manny’s defense might cost one full win over the course of a year relative to these options, but his addition still pushes the Dodgers ahead of the Diamondbacks in the NL West projections.

A-Rod would actually rank 12th on that list, as I neglected to include the 0.340 runs per game gap between the Astros’ Lance Berkman (0.259) and replacement Aaron Boone (-0.081) because my calculations showed the ‘Stros would actually disappear into a giant Vortex of Suck before that could become a reality.