There has been lots of talk lately about bringing Corey Koskie back to Minnesota. Koskie's time with the Twins has come and gone, though, and I see no real reason the Twins should bring him back, and I see a lot of reasons why the Twins won't bring him back.
The Twins offered Koskie a 2-year contract a year ago, and weren't willing to go to 3 years because they were worried about his health. Well, last year he continued his obvious pattern of decline in games played (153, 140, 131, 118, 97). Even if he goes back up to 120 or so, that's a lot of games to have to put someone else at the hot corner, and Koskie's certainly not helping the walk-up ticket sales on the DL. So, the Twins would be on the hook for the season they wanted the least, and a season they didn't want at all from a guy with an even worse injury history than he had when they didn't sign him.
Koskie bats left-handed. Koskie would give the Twins a third hitter (in addition to Mauer and Morneau) who is markedly worse against left-handed pitching--giving the Twins a much less consistent offense. From 2003-2005, Koskie hit only .223/.302/.345. That's Tony Batista, but without the power. Last year in particular, he was really bad, at .211/.269/.312. Considering that one of the team's best hitters by the end of the season is likely to be Kubel--also left-handed--this presents more lineup issues that the Twins had somewhat resolved by letting Jacque go.
Koskie's defense ain't what it used to be. His various and sundry injuries haven't just kept him off the field--they've affected his play on the field. Koskie's last season with the Twins, his defense was well below his customarily level of play, and there's no real reason to think it's going to be back to what it used to be. Checking out Tangotiger's UZR for 2000-2003, Koskie was one of the best defensive 3B in the game, clocking in at 12 runs/162 games above average. Those numbers aren't publicly available after 2003, though, but the Baseball Prospectus defense numbers basically agree on Koskie, having him at 17, 16, and 11 runs above average in 2001, 2002, and 2003. However, in 2004, Koskie swung all the way down to 8 runs below average. He improved to 4 above average last year, but it's clear from these numbers and observations of his play that overall his defense isn't what it used to be.
Terry Ryan has some pride, just like everyone else. Trading back for Koskie is proclaiming to the world "Looky Here!!! I made a big mistake letting him go!" Admittedly, I don't think this would be the driving force behind the decision, but you have to think it's a deterrent.
Maybe, maybe if the Twins traded for Koskie, he'd surprise us and play like the old Koskie we remember so fondly. But all signs, even just the fact that the Blue Jays basically just want to unload his salary, point to a large decline in Koskie's abilities. Is that someone we really want to give up talent, salary space, and a roster spot for? I'll keep my memories of his contributions to the Twins and hope there isn't a reunion tour, thank you very much.