The 2017-18 offseason saw the additions of Addison Reed, Zach Duke and Fernando Rodney to the bullpen, which gave fans some added excitement going into the season.
Duke and Rodney were as good or better than advertised, but Reed had the worst year of his eight-year career. With the Twins more or less out of contention by the All-Star break, two-thirds of those additions were traded along with Ryan Pressly and the Twins bullpen ended up with the 18th ranked bullpen according to FanGraphs WAR.
Heading into this offseason, the bullpen should again be a point of focus for the team as they look to support a promising starting rotation. Let’s start by looking at who the Twins currently have in-house coupled with a couple of free agency options at the end of the article.
May was far and away the best relief option once he returned from Tommy John surgery. His 13.3 K/9 as a reliever — takes out his “opener” appearances — put him at the top of the list of Twins relievers who have pitched at least 20 innings.
His 2016 mark of 12.7 is now sixth best all-time. Furthermore, his solid 3.20 ERA was a little inflated as his xFIP was 2.46. He doesn’t have an overpowering fastball — 94.4 mph is slightly above league average — but when that baby his pumped high and outside it results in a pretty good strikeout pitch.
According to Brooks Baseball, May adds about a quarter of a mile per hour on his fastball in a two-strike count and throws it 59.2 percent of the time. Below is a whiffs per swing chart that shows the progress that his fastball and curveball — the two pitches he throws the most — made from 2016-18.
Over his three-year major-league career, Rogers has established himself as a solid, consistent relief option out of the bullpen but really took a step forward in 2018.
He posted career bests in strikeout rate and home run rate while maintaining a great walk rate (6.2 percent). Like May, he doesn’t have an overpowering fastball but — unlike May — he relies on the movement of his pitches to fool batters.
A comparison of the horizontal movement between the two pitchers is graphed below. In 2018 he redeveloped his slider, which in turn lead to more success with the curveball which is his “out pitch.”
See, his slider and curveball have the same arm action and release point, but his slider is 5.0 miles per hour faster and has less of a sweeping motion compared to his curveball which moves an average 3.7 inches more across the plate.
According to Brooks Baseball, his whiff percentage on a two-strike curveball went from 19.7 percent in his first two seasons to 28.0 percent last season.
Hildenberger was a 22nd-round pick in 2014 who fast-tracked to the majors in about three calendar years. That alone is pretty impressive, and when he had similar success in 2017 the Twins thought they had found a diamond in the rough, so to speak.
Then 2018 happened.
To be fair, 2018 wasn’t awful as he pitched at replacement level with a 0.0 WAR according to FanGraphs, but it was a significant decline compared to his 0.8 WAR in 2017.
So what happened? Quite simply — hitters figured him out.
Often when you see a positive or negative change in results you can look at some “behind the scene” metrics like a change in velocity, pitch movement and/or in mechanics. According to Brooks Baseball, Hildenberger metrics in all of those areas were pretty similar from 2017 to 2018.
Comparing the two seasons, he struck out fewer hitters while walking more and was hit harder in 2018 — which you can see below from Baseball Savant.
Entering 2019, Hildenberger will have a role within the bullpen but it will remain to be seen if he can be trusted in high leverage situations. For now — and every bullpen has a guy like this — he will bridge the gap between the starters and the aforementioned relievers.
Like Logan Morrison, Reed was a very good and relatively cheap signing prior to the 2018 season.
Unfortunately — like Morrison — Reed went on to have the worst year of his eight-year major league career.
The culprit seems to be his go-to pitch, which is his fastball that he throws almost 70 percent of the time. Compared to the previous seven seasons, his fastball lost more than two miles per hour — and was over three miles per hour after he returned from injury — which should be a huge red flag for him and the Twins.
In 2012, Bill Petti — now of Hardball Times — provided the following research on the FanGraphs blogs.
According to this data, only five percent of pitchers that lost velocity in their age-28 seasons were able to regain some of their velocity. That’s not a good sign.
The biggest hope that the Twins have is that — even after returning from a triceps injury in late July — he still wasn’t fully healthy and will be able to use this offseason to recover.
It really won’t be until late Spring Training where we will have an indication whether Reed can bounce back in 2019. If some of his velocity is back he will fill a similar role to Hildenberger until he proves he can get hitters out.
If his velocity is not back, then he will have to rely on his command which was significantly better in August and September than it was in prior four months.
The Twins will have various pitchers competing for the fourth and fifth spots in the rotation, and it is very possible that they decided to keep a couple of those guys in the bullpen at the big league level. Here you can find my list of pitchers who could fit this role.
The Twins need to add one bullpen arm via free agency and preferably add two. In his Free Agent Buyers Guide and Offseason Blueprint, Brandon Warne suggests David Robertson and Cody Allen as good fits for the Twins.