If I keep hearing rumors like this, I am going to have no choice but to come out of retirement. There are three main reasons that I'm against signing Casey Blake as a free agent.
1) Blake is barely better than a platoon of Harris and Buscher would be, and might be worse.
2) The Twins would need to pay Blake at least as much as they committed to Mike Lamb last offseason.
3) The Twins already have a player with Blake's exact skillset who is five years younger: Michael Cuddyer.
To expound on these points:
1) Let's look at career numbers, which, given everyone's age, should overstate Blake's 2009 abilities compared to Buscher and Harris:
.297/.354/.411 -- Buscher vs. RHP
.266/.330/.436 -- Blake vs. RHP
.295/.360/.440 -- Harris vs. LHP
.258/.345/.478 -- Blake vs. LHP
Now, Blake only takes up one roster spot, so that helps his value compared to the platoon, but looking at various defensive stats, it looks like Blake is probably about as bad as Buscher defensively, maybe worse, and I think certainly worse than Harris is defensively at third.
Blake could also be a decent backup for Morneau at first base, and even give the Twins a viable long-term backup in case Morneau hits the DL, but I'll talk more about this in #3.
2) Paying Blake even $3-5M this year is too much money to commit to him, and with the number of teams that are interested in him, he's going to get multiple years. It's one thing to invest in a 35-year-old player who is a special player, but Blake is not a special player. He's carved out a nice career for himself, but whoever pays Blake is going to be paying for the 31-34-year-old Blake's performance while getting the 35-37-year-old Blake's performance. This is not a good idea for a team that operates under financial constraints.
Going into 2008, PECOTA had Blake with a 21% attrition rate and a 28% collapse rate. Being another year older is not going to help those numbers. For comparison, Lamb was a bigger risk of fail this year: 30% attrition and 39% collapse. Regardless, I don't know why the Twins would want to bother with the risk that they'll have millions tied up in a guy who has a decent chance of falling apart with a limited upside (league average hitter who is a defensive liability.) It's fairly amazing that Blake hasn't fallen apart yet--unathletic guys tend to age poorly--but I don't think the smart money is on him continuing to be decent.
3) Career stats:
.264/.334/.447 -- Casey Blake
.268/.344/.441 -- Michael Cuddyer
Both of them are not good defensive third basemen and fit better defensively as corner outfielders or first basemen. Any mention of Cuddyer of course brings us to the "problem" of Gomez, Span, Delmon, Kubel, and Cuddyer all being outfielders. An equal rotation of five guys into four spots (LF, CF, RF, DH) would give each of them one day off every five days, but eventually one of them is going to get hurt anyway, at which point they become everyday players and I'm not even sure who the OF backup would be at that point. But Gardy could certainly do better than just having them sit out all game on their days off. If Span or Gomez is on the bench to start the game, he could come on for someone as a defensive replacement. If Delmon, Cuddyer, or Kubel is on the bench to start the game, he could come to pinch-hit in a key spot.
Additionally, it seems quite obvious to me that Morneau needs more days off. Or at least more days where he's not in the field. For his career now, Morneau has hit .296/.359/.533 in the first half of the season and .267/.337/.464 in the second half. In the past it may have made sense to keep him on the field because our backup options suck, but if say Cuddyer was going to DH a number of times anyway, then we could instead put Cuddyer on the field at first base and put Morneau at DH, where he gets a little more rest. Neither one of them is a very good fielder, so that doesn't especially make a difference from where I sit. (And while we're talking about days off, it sure seemed like Delmon and Gomez responded well to the occasional day off, so more days off keeping everyone's legs fresh sure seems like a good idea for a team that depends so much on speed.)
On top of that, I really don't know who you'd get rid of. Obviously, there are things I don't like about Delmon's game, but those are obvious to everyone at this point, and I'd rather not sell low on Delmon. Span and Gomez are both cheap and I'd be fine keeping them around. Kubel is limited, but he's pretty good at what he does well (hit right-handed pitching) and I don't think there's a huge market out there for him. Realistically, I can't see the Twins even considering trading Cuddyer, given his clubhouse leader and general good citizen status. Plus, with his injury last year, we'd be selling low on him, too. This isn't a situation like having a can't-miss prospect catcher at the same time your current catcher just had a career year--whatever surplus current exists in the Twins' outfield isn't that much of a surplus and none of these guys are flawless.
To make a final point: WTF do the Twins do with Harris if they sign Blake to be an everyday third baseman? As far as I can tell, giving up on Harris as a third baseman now would be essentially the same as giving up on Blake as a third baseman back in 2003. The Twins can't undo the Blake Mistake, but they can keep from repeating that particular mistake. Harris should only be used in the middle infield in an absolute pinch. He's a corner infielder. He's not a terribly good corner infielder, but he can be mediocre there, and certainly as part of a platoon he can help the Twins out, and while I'd rather have a defensive guy as the backup SS, you could do worse than Harris as your backup SS.
So I really see no reason to spend some of the Twins' precious little money on Casey Blake. Where the Twins really need help is at SS or 2B. Tolbert at SS or 2B is a bigger problem than Buscher/Harris at 3B, and the Twins have only one guy (Casilla) who I would feel comfortable as an everyday player at 2B or SS. Getting more help in the bullpen should also be more of a priority than overpaying a soon-to-be-washed-up third baseman. I would love it if the Twins had more power, but Blake isn't going to make the Twins a better team, so I'm not interested in his power.

If this will get you out of retirement, ubes, I'll start planting some rumors myself.
Ditto. Great to see that byline, ubes.
What are your thoughts on Rockie's 3B Atkins or Atlanta SS Escobar--two other players Joe C said the club was interested in? Neither are free agents, so talent would need to be surrendered to acquire them. Are they worth giving up one of our starters? Methinks Perkins couldn't pry them away from their respective clubs unless incriminating photos of club officials were involved.
I don't know much about Escobar, but I'm not a fan of going after Atkins. His road stats haven't been very good for a couple years now (really bad this year) and he's about to get expensive. I'd gladly take him back for Perkins, but not for any of the other young starters.
I'm with you on this one Ubes; a 3-year contract to a mediocre 35-year old 3B is just a bad idea for a team with the Twins' limited resources.
I'll just focus on what I think of Escobar and Atkins--for every player there is a right price in a trade. (Though I will say that I am super pessimistic about Perkins' future and that he may never look this good again.)
In 230 games as a 23-24-year-old, Escobar has been an above-average hitter and what seems like a league average or slightly above league average fielder. That's a quality player. He was only at about 25 VORP last year, but 25 VORP would have made him our 3rd-best everyday player. Well, Span probably passes him in overall value since he's probably a better fielder relative to his position than Escobar, but still, you're looking at someone about that good. Not a superstar, but probably a fringe All-Star many years and an All-Star in a career year.
Generally speaking I would stay far, far away from Atkins. He has a career 108 OPS+, which is definitely solid as far as hitting skills go, but PMR rates him as a very poor (worst in the majors in 2007) fielder at third base, so I would say that it's more appropriate to think of him as a first baseman playing out of position, much the same way that Harris was a third baseman playing out of position in Tampa. Atkins has stayed healthy, but at 29, he's starting to get old and the poor fielding probably means he's not all that athletic, so I would be scared about his aging curve. If you park adjust his raw numbers the last three years, he had 26, 23, and 19 HR, and got a boatload of at-bats. I'm not impressed.
As far as third basemen we could get in a trade, Adrian Beltre has a career OPS+ of 107, and would be in a contract year next year. He's also probably 30-35 runs better than Atkins on defense (though I think age and minor injuries throughout his career may be beginning to hinder his defensive abilities somewhat), which makes a huge, huge difference. If the Twins aren't contending at the deadline, he could be flipped, or they could let him walk for draft picks at the end of the season. I don't know what it would take to get him, but there was a dialog with the previous GM, who knows what the new GM would be looking for. Word is that they don't expect they can re-sign him, so he'll certainly be on the block.
While I'm at it, the other two names in the blender are Kevin Kouzmanoff and J.J. Hardy.
Kouzmanoff is about a league average hitter, but appears stretched defensively at third base. I might not go so far as to consider him a first baseman (like I said with Atkins), but he certainly gives away some of his value on defense. In fact, with an 11 VORP last year, he may well have overall been a replacement level player. It seems unlikely that he's a significant upgrade over Brendan Harris, if he's even better in the first place.
PMR really liked Hardy this last year, though he had a weird RZR/OOZ split this year--a below average rating on plays within his zone, but a ton of out-of-zone plays. He's probably an average fielding shortstop, but he had a 113 OPS+ last year and seems to be improving year-by-year at the plate. He could well be the best player in this entire discussion, but I'm not totally convinced about his defense. My vague recollections of watching him play made him seem like he had a strong arm and maybe not good hands (though that could just be me trying to justify his weird RZR/OOZ splits) and I haven't been impressed with his range, but I'm not sure. I have to imagine he would cost us a lot of talent...
I think you are missing one thing in your analysis ubes, Blake's "grittiness". That alone is worth $10 mil!
True, true...though I hear Willie Bloomquist is even grittier than Casey Blake...and there may even be some collegiate punters on the market...
It was nice to see this Ubes-- With SBG's call to arms I was getting very close to writing a much more cluttered version of this very post.
Thank you for saving me the embarrassment.
From the point where you put the five-outfielder situation in the derisive quotations it deserved, I was (almost) literally cheering you on (it's late and people are sleeping). I hope that Twins management has a similarly clear view of the situation and avoids parting with any of the 5 amigos.