Have The Royals Found Another Rule 5 Gem?

After selecting Joakim Soria out of the Padres’ farm system in the 2006 Rule 5 Draft, it could be argued that the Royals are still in the “playing with house money” honeymoon phase of the Rule 5 process.  After all, even landing a Rule 5 player who can stick on a Major League roster for an entire season is a success, never mind landing a two-time All-Star like Soria through his 2007-11 heyday as Kansas City’s closer.

Eleven years after drafting Soria, it seems like the Royals again struck gold via the Rule 5 process.  While Brad Keller has yet to reach All-Star levels, the right-hander has already enjoyed enough success over his first two MLB seasons that he looks like a solid building block for a young K.C. team.

Keller was an eighth-round pick for the Diamondbacks in the 2013 draft, and through five pro seasons had compiled some decent but unspectacular numbers in the Arizona farm system.  Over 130 1/3 innings for Double-A Jackson in 2017, Keller posted a 4.68 ERA, 7.6 K/9, and 1.95 K/BB rate, which wasn’t quite good enough for him to make the grade amidst something of a 40-man roster crunch for the D’Backs.

Coming off a 93-win season and a NLDS appearance in 2017, the Diamondbacks were focused on using much of their available 40-man spaces on players who could potentially provide immediate help in 2018, as GM Mike Hazen explained to the Arizona Republic’s Nick Piecoro two years ago.  “Our scouts liked [Keller]. We liked him,” Hazen said.  “We made the conscious decision not to add him because of where he was in proximity to the Major League team, where we were in the cycle, what we wanted to use our 40-man spots for, we wanted to be aggressive in the offseason in claiming guys…that were closer to the big leagues in our mind.”

So, the D’Backs left Keller unprotected in December 2017 draft, and it didn’t take long for another team to pounce on the right-hander.  However, that other team wasn’t actually the Royals, whose spot in the Rule 5 draft order didn’t fall until the #18 spot that year.  Instead it was the Reds who took Keller with the fifth pick, and then promptly dealt him to Kansas City for cash considerations.  (The Royals swung a similar move just one pick later, acquiring sixth pick Burch Smith for cash from the Mets after New York selected Smith out of Tampa Bay’s farm system.)

Smith also ended up spending the entire 2018 season on the K.C. roster, though he was cut loose after posting a 6.92 ERA over 78 innings.  Keller, on the other hand, was much more of an immediate success.  After posting a 2.01 ERA over his first 22 1/3 frames of work out of Kansas City’s bullpen in 2018, Keller was promoted to the rotation and continued to succeed.  The righty had a 3.28 ERA over his 20 starts, striking out 83 batters (against 43 walks) over 118 innings.

Keller’s sophomore year wasn’t quite as impressive, though he still managed a quite respectable 4.19 ERA, 1.74 K/BB, and 6.6 K/9 over 165 1/3 frames, all as a member of the Royals rotation.  It could be argued that Keller was perhaps fortunate to manage that 4.19 mark, as some ERA predictors (4.94 xFIP, 5.23 SIERA) were significantly higher, and batters made much more solid contract off him in 2019 than in 2018.  The Statcast metrics also took a dim view of Keller’s 2019 performance, with a whole lot of blue — as in, below-average — numbers for Keller in comparison to other pitchers in exit velocity, xwOBA, strikeout percentage, and several other categories.

That said, advanced metrics don’t tend to favor low-strikeout hurlers like Keller who specialize in keeping the ball on the ground.  Among pitchers with at least 300 innings tossed over the last two seasons, Keller has the lowest (8.4%) home run rate in baseball, and the second-highest (52%) grounder rate.  These outstanding numbers are particularly valuable in this era of the lively ball, and Keller could further benefit from some improved defense behind him, should Maikel Franco provide any sort of upgrade at third base.

All told, 4.8 fWAR over two seasons already represents a very nice return on the Royals’ initial minor cash outlay to Cincinnati.  Keller doesn’t turn 25 until July, and he doesn’t reach arbitration eligibility until this coming offseason, putting him under the Royals’ control through the 2023 campaign.  Under normal circumstances, Keller could be a player the Royals might have already locked up to a contract extension, and while all extension talks are halted under the current transactions freeze, it wouldn’t be a surprise if K.C. began some talks with Keller’s representatives once regular business gets back underway.

While truly major Rule 5 Draft success stories are relatively few and far between these days, a team only needs to hit on one pick to make the enterprise worthwhile.  Finding a big league talent for virtually nothing is a win for any team, and if that talent is a mid-20’s starting pitcher who looks like he can hang in at least the middle of a big league rotation, the Royals got a valuable boost to their latest rebuilding effort.