KC Royals Projections: Full season awaits Jesse Hahn

An excellent 2020 gives a KC Royals pitcher hope for a good full season.

Welcome back to Kings of Kauffman’s KC Royals Projections series for 2021. Between now and Opening Day, our writers are analyzing how various Royals performed last season and predicting how they might fare this year. Up today is pitcher Jesse Hahn.

Deep in the winter of 2018, when the KC Royals were preparing to take on the challenges brought about by the inevitable loss of much of their two-time World Series nucleus, they took a step designed for incremental improvement. They traded Ryan Buchter, the only positive component of the previous campaign’s infamous deal that saddled Kansas City with Brandon Maurer, and Brandon Moss to Oakland for pitchers Heath Fillmyer and Jesse Hahn.

Fillmyer, who’d never pitched in the major leagues, appeared in 29 games for KC across 2018 and ’19 before the Royals let him go. Hahn, on the other hand, brought four seasons of big league experience to a staff in need of help the team believed he could provide—the righthander went 7-4 with a 3.07 ERA in his 2014 rookie campaign with San Diego, then 6-6, 3.35 for the A’s before a midseason flexor tendon ended his 2015 season. Probably plagued by the injury’s aftermath, Hahn was 5-10 over the next two years before Oakland shipped him to Kansas City.

The new Royal was also the beneficiary of successful Tommy John surgery before his professional career even started. Tampa Bay chose him in the sixth round of the 2010 draft, but the UCL injury and operation delayed his minor league debut until 2012.

Although repaired, the UCL struck again after Hahn’s trade to the Royals. This time, the trouble forced him to the since-renamed DL in early March, and he only managed limited minor league rehab work before undergoing “primary repair” surgery, an alternative to the more common Tommy John procedure. He didn’t pitch for the Royals until late in 2019; he gave up seven runs and walked six in just 4.2 innings, although he struck out seven.

Last season, then, became pivotal for Hahn. He spent time on the bereavement and paternity lists, but none on the IL, and made the best of his 18 appearances in the pandemic-shortened campaign. Pitching better than he had since 2015, Hahn surrendered only a run (0.52 ERA) and struck out 19 over 17.2 innings. He became one of manager Mike Matheny’s most reliable relievers.

Baseball Reference and FanGraphs projections for Hahn’s 2021 season

Baseball Reference and FanGraphs don’t believe Hahn will enjoy the kind of success he had last season. Baseball Reference projects a 3-3, 4.22 campaign, with a 4.0 BB/9 (down a couple of ticks from 4.2) and 9.2 SO/9 (a drop from 9.9). FanGraphs (Depth Charts version) predicts he’ll win three and lose three, and post a 4.35 ERA, 4.25 BB/9 and 8.51 SO/9.

How will Jesse Hahn actually perform for the KC Royals this season?

Barring injury or a pandemic-driven schedule reduction, 2021 offers Hahn the promise of his first full season on the mound with Kansas City (unless, of course, he becomes one of the two players the Royals still need to give Boston to complete the Andrew Benintendi trade). Primarily a starter before joining the Royals, he’ll return to the bullpen—expect him to play a significant mid-to-late inning role.

Duplicating the kind of season he had last year will be difficult, if not impossible. Pitchers simply don’t turn in full campaign 0.52 ERAs anymore. But if Hahn can improve his control a bit, maintain or approach his 2021 strikeout rate, and avoid injury, an effective, 50-appearance, 3.00-3.50 ERA (or lower) season isn’t out of the question.

The KC Royals and Jesse Hahn are looking forward to a full season. It could go well for both.