Milwaukee Brewers should consider converting Adrian Houser to relief role to bolster bullpen

As the trade deadline approaches, relief pitching is on the shopping list for the Brewers. By ERA and most estimators, the relief corps ranks in the top 10 among the 30 Major League clubs, but it could use some more depth. Josh Hader has been excellent, and Devin Williams has held his own despite some concerning trends, but everyone behind them seems to be higher on the totem pole than they should be. Brad Boxberger has been solid for much of the year, but recently began experiencing control issues. Brent Suter has been similarly effective in a middle relief role, but he is allowing over one hit per inning, which is not ideal for high-leverage situations. Rookie Jake Cousins has looked excellent in his debut season, but he lacks experience.

While corner infield help should still be the top priority to address, the bullpen could benefit from adding one or two arms that can handle high-leverage situations or at least bridge the gap to Williams and Hader in the middle innings. However, the David Stearns regime has demonstrated a willingness to plug holes in an outside-the-box manner if the obvious solution is not available for a price they deem suitable. The Brewers just might have the answer to their lacking relief depth currently on the roster in the form of Adrian Houser.

Moving the 28-year-old to the bullpen would not be a demotion, as he has effectively filled a spot near the back of Milwaukee’s rotation. In 82 ¹⁄₃ innings of work, Houser has posted a 3.94 ERA, 4.64 FIP, 4.65 xERA, 4.34 SIERA, and 4.24 DRA. At this point, we have a pretty clear idea of who Houser is as a starting pitcher: a traditional pitch-to-contact sinkerballer who can capably slot into the back of a rotation. Since the start of the 2020 season, Houser has worked to a 4.49 ERA, 4.71 FIP, 4.39 SIERA. He has posted an excellent 59.6% ground ball rate and a below-average 18.4% strikeout rate. The run prevention figures are not especially exciting, but eating innings has allowed Houser to be above replacement level.

While he has shown that he can provide value as a starter, the right-hander’s approach in the role limits his ceiling. He has one of the best sinkers in the game, but it is his only effective pitch. Each of his secondary offerings has been below-average, per Statcast.

Baseball Savant

Because of this, Houser is locked into a pitch-to-contact approach, which makes him more vulnerable to rough outings. It also makes him unlikely to ever become anything more as a starter than what he is now.

Houser does have past experience working out of the bullpen, primarily in 2019. While he worked just 30 ²⁄₃ innings in the role before joining the rotation for good, there are some dramatic differences to prove that Houser is a much different animal as a reliever.

As a reliever, Houser induces swings and misses at an above-average rate. Much of that is due to increased velocity. When pitching in shorter stints, he sits in the mid-to-upper 90s. When stretching himself out, he loses a tick on both his sinker and four-seam fastball. As a reliever, Houser gave opponents a balanced diet of sinkers and four-seamers. The latter held opponents to a .251 wOBA with a 40% whiff rate. He was more aggressive with it, too. Not only did he frequently elevate the four-seamer, but he attacked the zone in general and used the extra velocity to blow guys away.

Baseball Savant

The four-seamer used to be Houser’s most-used pitch in two-strikes counts. Here are just a few examples of Houser climbing the ladder with mid-90s heat to induce swings and misses, something he rarely does as a starting pitcher.

You’ll notice that this compilation includes plenty of awkward swings from left-handed hitters. That is because having an electric fastball as a reliever helped to neutralize the dramatic platoon split that has plagued Houser as a starting pitcher. Since the start of the 2020 season, he has held right-handed hitters to a .216 batting average and .287 wOBA. Lefties, meanwhile, have slammed him for a .313 average and .382 wOBA, primarily due to his lack of an effective secondary pitch. Reliever Houser was dominant against hitters from either side: a .216 wOBA against righties and a .243 against lefties.

Now that he has been stretched out as a starter, the extra velocity has disappeared from Houser’s heater. After hitting 95 or greater 156 times in his stint as a reliever, he has done it just 113 times over the past two seasons combined. His four-seam fastball usage has been on a steady decline, giving way to even more sinkers. When Houser does throw his traditional fastball, it lacks life and has been hit around to the tune of a .386 wOBA. The whiff rate against the pitch has dropped to 26.8%.

If the Brewers were to shift Houser back to the bullpen, it would require the acquisition of another starting pitcher. The easiest way to beef up the relief unit is to simply acquire a high-leverage arm or two. Ultimately, it comes down to how this year’s trade market plays out.

It is also important to remember how Stearns and his staff have historically approached the trade deadline. They are always focused on where they can find the best value without having to sacrifice too much young talent, not if it is a clean fit or a conventional way to plug a particular hole. When the Brewers needed an upgrade at second base in 2018, they traded for Mike Moustakas and moved Travis Shaw, who was an excellent third baseman at the time, to the keystone. Shaw had never played the position in his life, but ultimately, it worked out. The following year, the Brewers upgraded their bullpen by trading for struggling starter Drew Pomeranz and converting him into a lights-out reliever.

This is an organization that is not afraid to be unconventional in addressing needs. Acquiring a mid-rotation starter and telling Adrian Houser to let it eat for three-to-six outs at a time is a potential option that should be under consideration.

Statistics courtesy of FanGraphs, Baseball Savant, and Baseball Prospectus.