In just over a year at the helm as the Milwaukee Brewers’ general manager, David Stearns has shown an incredible ability to find value in places where no one thought to look. By buying low on Jonathan Villar, re-signing Hernan Perez, and betting against Keon Broxton’s strikeout problem, Stearns has accumulated assets without giving up any real assets in return.

Perhaps the best example of this ability is the acquisition of thirty-one year old rookie Junior Guerra. The right-hander was one of many feel good stories for the Brew Crew in 2016. After throwing just four career major-league innings prior to the 2016 season, he posted a 2.81 earned-run average in 121 2/3 innings, a result not even Guerra himself expected. Although Brewer fans don’t want to hear it, it is unlikely the soon-to-be thirty-two year old sophomore can keep up that type of production. I’d argue that it’d be wise for the Brewers’ front office to sell on the value Junior Guerra built up in 2016 before Opening Day 2017.

On the surface, it looks as though Guerra had a superb rookie campaign. With a deeper inspection, that observation changes. With his 2.81 ERA, he outperformed his 3.75 FIP and 4.43 DRA. He had the fifth lowest BABIP among pitchers with over 100 innings in 2016, at .250. There is no reason to believe Guerra can sustain this BABIP suppressing ability. While the Brewers’ defense will be improved with a full season from Orlando Arcia at shortstop, they project to be about average in the field. Guerra does not have the Chicago Cubs’ world class defense behind to keep his BABIP down. While he was slightly above average at inducing pop-ups and suppressing line drives in 2016, it is not enough to believe he is a FIP-beater. Guerra’s BABIP will not stay in the .250 range, it should shoot up to at least the .280-.300 range and in the end his numbers will look much different.

Not only was Junior Guerra helped by a suppressed BABIP due mostly to luck, but he was incredibly lucky as far as where he pitched and who he pitched against. He had the third lowest oppOPS (.710) out of 138 pitchers with at least 100 innings in 2016. In other words, he faced almost the easiest competition possible. Level of competition is easy to overlook. It is often assumed that differences in competition even themselves out over the course of a 162-game season. There are major differences not only between the two major leagues with the designated hitter rule but between divisions and even in the divisions themselves. It is hard to determine the type of competition Guerra will face in 2017 but it is safe to assume it will be stronger.

The average sabermetrically-minded baseball fan with any knowledge on park factors would say that Miller Park is a hitter-friendly park. They would be correct when looking at numbers from 2015 or any other year since the opening of the Brewers home ballpark in 2001. The 2016 season was a different story. Miller Park actually played as a slightly pitcher-friendly park. Right-handed batters saw no park factor, positive or negative, whatsoever. Left-handed hitters actually had a park factor three percent below average. Not only did Guerra face the third easiest competition among pitchers with over 100 innings, he did it pitching in slightly pitcher-friendly ballparks. Overall, Guerra had a PPF of 94, six percent below average. If Miller Park plays more like the hitter-friendly park it has historically been, Guerra could have problems he didn’t face in 2016.

There is a Catch-22 when it comes to selling high on Junior Guerra. There’s no doubt front offices are informed on just how well the circumstances played out for Guerra in 2016. He will not be acquired for the price his 2.81 ERA suggests. He is likely to be acquired for closer to what his 3.75 FIP suggests. Upon closer inspection, I’d be wary of paying that asking price. If David Stearns can find a reasonable deal for Guerra before Opening Day, he’d be foolish not to take it. I don’t see much room for an already aging thirty-one year old starting pitcher to gain value. Even if they kept him, he likely won’t be a real contributor on the next winning Milwaukee Brewers team in 2018 or 2019. The circumstances will not be as favorable in 2017 as they were in 2016 for Junior Guerra. If he is given an opportunity to build on his already unsustainably high value, it is likely his flaws will be exposed and the Brewers will be left sitting on a once valuable piece that is now worth nothing.