The Twiins put up their Duke

The signing of Zach Duke became official Tuesday evening, and as I implied in that morning's post, I'm not impressed.

I understand the logic. He's a high-floor, low-ceiling veteran reliever. Gabriel Moya, the prospect who tore up Double A last year and got a cup of coffee in September, has a higher ceiling but a lower floor. Bringing in Duke to be the second lefty in the bullpen is an exercise in risk avoidance.

That said, I doubt the Twins' postseason chances hinge on the bullpen's second lefty. If  Buddy Boshers and Craig Breslow couldn't cripple them last year, Moya isn't likely to either. And I strongly dislike seeing a kid with an 0.77 ERA in the Southern League get logjammed by a journeyman.

The Twins clearly like Duke a lot more than I do. I see him as a non-roster invitee candidate; they gave him a 40-man roster spot and a $2 million contract.

Presumably Moya is now ticketed for Rochester. If he puts up a 0.77 ERA there too, he won't stay there long. Heck, if he triples the ERA, he'll move up.

Supposedly the Twins think Duke can get both lefties and righties out. He certainly hasn't been used that way. Since he became a bullpen guy, he's never had a season with more innings than appearances, and the ratio is seldom close. Paul Molitor has not been very inclined to one-out relievers so far.

The numbers are of limited use at best here. Duke had a better OPS against righties than lefties in 2017, although that's a slender reed to lean on. He only faced 31 righties all season. For his career, his platoon splits are rather lopsided -- .809 OPS (On-base Plus Slugging) vs. righties, .705 vs. lefties -- but even there, we're mixing his early career as a starter in with his relief work.

Plus there's the injury factor to cloud things. Duke pitched last year in a rapid return from ligament surgery, and I've seen some reports that his stuff improved as the season progressed. I am sure the Twins have a better grasp on what Duke is now as a pitcher than I do.

Bottom line: I'm not thrilled, but even if the signing is a failure, it won't cripple this team.