The Twins have been taxing their bullpen lately and are amidst a stretch of 20 games without a day off, so it makes sense that they decided to send down Matt Carson – who became the fifth outfielder after Denard Span returned Thursday – in exchange for relief help.
The pitcher they called upon is Kyle Waldrop. This is his second time getting the nod this year, and he only missed a spot on the Opening Day roster because of an injury. It seems clear that the Twins are very high on him, but it's not very clear why.
Standing 6'5", Waldrop gets a nice downward plane on his pitches and induces a lot of ground balls. In that sense, he's got some potential. At the same time, he doesn't miss any bats. For his career in the minors, Waldrop has averaged 5.7 K/9; for comparison, Nick Blackburn posted a 5.5 mark in his minor-league career.
It's certainly possible for a reliever with a substandard strikeout rate to be effective if he limits walks and keeps the ball down, but Waldrop's K-rate is beyond substandard. Given that he's averaged 5.7 whiffs per nine innings (including 5.2 above Single-A) there's a good chance he'll rank among the most contact-heavy relief pitchers in the majors.
Currently only two MLB relievers have a K/9 mark below 5.0 – two of them are on the Twins (Alex Burnett and Jeff Gray). Do they really intend to move forward with a bullpen filled with guys that can't come in and get a strikeout?
At this point, the Twins' sole focus should be evaluating players for next year and beyond. In order to give Waldrop another look, they bypassed players like Anthony Slama – who is healthy again and back to putting up cartoonish numbers in Triple-A – and Deolis Guerra, who will be out of options next year. Guerra has a bloated ERA in Rochester right now thanks to a home run spike, but his 50-to-21 strikeout-to-walk ratio in 51 innings is far superior to Waldrop's horrible 16-to-13 in 39 innings. Given his previous ranking as a top prospect and his general success since converting to relief duties, you'd have to think that Guerra is more likely to be a long-term bullpen asset than Waldrop.
Speaking of long-term bullpen assets, Gray very obviously is not one. Why is he still on the roster and holding some of these other guys back? Not only has he been one of the least effective relief pitchers in the game this year, he's 30 with a terrible track record and virtually no upside. His future with the organization won't last past this year (you'd hope) so why do the Twins continue to give him innings while missing an opportunity to work with younger arms that they need to make decisions on, such as Guerra and Slama?
It's been one of the most befuddling aspects of this season, but hopefully it will cease to be an issue when rosters expand in a week.