Last night's loss to the Rangers was ugly on multiple levels. First, the loss itself, coming with the A's right in the game but letting it slip from their grasp as the Rangers were able to take advantage of a bases-loaded situation to score the tying and go-ahead runs in the bottom of the eighth.

Second, and probably more importantly, was the multi-car pileup of injuries. First went Nomar, appearing to injure his calf straining to reach first base on a ground ball up the middle. He hit the DL today. Then went Mark Ellis, coming out of the box on his own ground ball but only being able to hobble about halfway up the first-base line. He also hit the DL today. Then was Brett Anderson, who was pitching a very nice game, but was knocked out by some sort of finger injury. One hopes it's not a blister, because those can be the kind of recurring issues that trouble pitchers. Then came Sandy Casilla. I'm not sure what happened to him, but he also had to leave with an injury. Neither Anderson nor Casilla have been placed on the DL yet, and Anderson is expected to make his next start. That, at least, is good news.

To replace one of the injured infielders, the A's brought up Eric Patterson. It remains to be seen what their other move will be. Right now, the mix for the second- and third-base spots is Eric Chavez, when he's healthy enough, Bobby Crosby, who can play either position, Jack Hannahan, who's really just a third baseman, and Eric Patterson, who's probably just a second baseman. Cliff Pennington would seem likely to be the other callup, as he's got some defensive versatility, as contrasted with Jeff Baisley and Gregorio Petit.

This is not exactly a world-beating lineup. Using PECOTA-projected MLVr, a lineup of Sweeney, Cabrera, Giambi, Holliday, Cust, Buck, Crosby, Suzuki, and Hannahan would be about 0.3 runs below average per game. (I'm not actually sure if MLVr can be used this way.) The league average runs scored per game is in the high fours right now, and the A's are scoring 4.17, so if everyone in this lineup performs up to PECOTA's expectations from here on out, the A's won't be losing anything on offense. Of course, Jason Giambi and Matt Holliday, two of the only three A's expected to be above-average with the bat (Cust is the other), are hitting far below average right now, so whether the A's offense gets turned around in this Ellis-and-Garciaparra-less period has much less to do with Pennington, Patterson, Hannahan, or Crosby than it does to do with the #3 and 4 hitters in the lineup actually hitting like they deserve to be in those spots.

Where the A's could get hurt is on defense. Mark Ellis is about a run over average on defense according to UZR (a rate of 7.5 over 150 games, a number very much in line with his career, except for his flukishly high 2008). Crosby hasn't put in nearly enough second-base time (just 14 innings) to make any defensive judgments, but we can make some assumptions based on the fact that it's still a brand new position for him. His awkwardness in turning a 6-4-3 double play last night was no inspiring, notwithstanding the fact that he did actually manage to convert the outs. Eric Patterson, over 177 innings at second in his big-league career, is a -15.8 fielder on a 150-game rate. If we take that as his true ability (and remember, there's a reason teams view him as an outfielder, not a second baseman), that's a 0.15 run per game drop at second base every time Patterson steps out there instead of Ellis. That's a pretty significant difference, especially in the low-run style the A's are playing (last in the league in offense, sixth-best in runs allowed).

Jack Hannahan at third base instead of Nomar is a more uncertain proposition. Hannahan's proven himself to be a very good defender, on the order of +10 runs per 150 games. In about 650 innings at third in 2005 and 2007, Nomar showed himself to be in the -12 range. On the other hand, he's got about 100 innings in '08 and '09 that put him at more like +5. Considering that he'd never played the position when he started in 2005, and that he spent 2006 at first before shifting back to third for 2007, it's possible he's figured some things out and is showing legitimate improvement over his initial forays at the corner. That said, let's call him, generously (remember, I've also been watching him play, including letting a ball go right under his glove last night), a -5 per 150 defender. That means that at third base, the A's would get a 0.1 run per game improvement every time Hannahan starts instead of Garciaparra. That more or less negates the defensive drop at second.

One lesson we can draw from this, by the way, is that the A's have a lot of replacement level players. Crosby, Garciaparra, Hannahan, Patterson, Pennington, even Ellis to an extent ... there's just not much drop-off when you start switching and swapping guys all over the place to cover injuries and days off and the general desire of a manager to stave off lineup boredom.