As we feared, Mike Lowell has been placed on the 15-day disabled list with an oblique strain.  Taking his place on the roster will be David Pauley, a pitcher who has had a relatively decent year in Pawtucket (3.32 ERA in 135.2 innings, 94/40 K/BB).  Pauley will serve as an insurance arm tonight after the 200 pitch circus last night at Fenway Park.  After tonight’s game, another move may follow, likely bringing up one of Jeff Bailey, Jonathan Van Every, or Chris Carter from Pawtucket.

We know what the loss of Mike Lowell means offensively.  Sean “The Mayor” Casey will be getting the majority of his at bats, with some also going to Alex Cora (shudder).  Casey can hit a little, albeit with terrible speed and little power.

However, this move will likely hurt the Red Sox more defensively than offensively.   When Kevin Youkilis slides over to the hot corner, his career RZR (Revised Zone Rating per The Hardball Times), weighted by innings played at 3B, hovers around .728.  Mike Lowell, in comparison, sports a 3-year weighted average RZR of .750.  Now, at first base, Gold Glover Youkilis has a weighted RZR of .804 for his career, while Sean Casey’s 3-year weighted RZR is .768.

Simply put, this 1B/3B tandem is going to make less plays, and Lowell’s absence will hurt the team on two fronts.

Note: I used 3-year RZRs for Casey and Lowell because they are in the proverbial “twilight of their careers” and thus more recent data would be relevant.