has allowed just 20
hits in 24 major league
innings, but four of
them have been
Of the pitchers on hand, there are two options for that job: Brian Duensing, who may be used instead in the rotation, and Tyler Robertson.
Assume that Duesning is rotation bound. Is Robertson really the lefty one wants to entrust with key at-bats late in games?
Robertson has worked 24 innings for the Twins since his call-up -- 24 innings spread out over 37 games, statistical evidence that he's used as a LOOGY (Left-handed One Out GuY). He has an ERA of 5.63, which is definitely unimpressive, and 25 strikeouts, which is impressive. He's also allowed four homers, which is one every six innings, and that's a high rate.
Twenty-four innings is not much of a sample size, but it's what we have to work with. And it can be argued that the job of a short reliever is to dominate small sample sizes.
Robertson has faced 67 lefties so far and just 38 righties -- again, he's a LOOGY, and Ron Gardenhire has been adept at getting him the matchups he should be effective in.
Left-handers are hitting .186/.258/.305, which is ... awesome. He's struck out 21 of those 67 left-handed hitters, and that's also very good. He's allowed two homers to lefties, but at least they were allowed to legit power hitters (Prince Fielder and Adam Dunn).
Right-handers are hitting .300/447/.500. Nine hits, two of them homers, and eight walks (although three of the walks were intentional).
My take at this point: To be a truly useful late-inning reliever, Robertson needs to be better at keeping the ball in the park, and he needs to be able to do something against right-handed hitters.
I think he'd be a better fit as the no. 2 non-closing lefty than as the top option. But doing that means either committing to Duesning in the bullpen, which the Twins seem unwilling to do at this point, or bringing in another lefty arm -- and that might complicate things if Duensing winds up back in the pen in spring training.