Jeremy Jeffress was part of the trade that sent Zack Greinke to Milwaukee in December of 2010. A power arm out of the bullpen, the Royals hoped Jeffress could fill that role at the major league level.

The only thing about Jeffress that we can say with any certainty, is he’s consistently inconsistent. That’s a fancy way of saying the guy really has a difficult time finding the strike zone. Sure, he strikes out plenty of batters. That’s thanks to his electric fastball. Unfortunately, with that electricity, comes an inability to harness that current. His best walk rate at any stop (more than 15 IP) is 4.6 BB/9. And that was at A-ball back in 2007.

Jeffress was a starter his first three full seasons as a pro, but moved to the bullpen for the 2010 season. It was kind of a hail mary on the part of the Brewers as Jeffress’ walk rate spiraled out of control in 2009 at Double-A when he posted a 10.9 BB/9 (yes, 10.9 BB/9) in eight starts covering 27 innings. The walks didn’t disappear when he moved to the pen, but there were signs his control was improving.

Still, he’s yet to master the strike zone.

Perhaps a longshot to join the pen at the outset of the 2011 season, he did nothing to win a spot. Nevertheless, the Royals decided to bring Jeffress with the big club. That was with eight walks and eight strikeouts in 12 Cactus League innings. It was a strange decision given the fact he had pitched only 10 innings at the big league level prior to the season. And there was that pesky control issue.

While he made the team, I can’t figure out the reasoning behind his usage last summer. Immediately, Ned Yost threw him into the proverbial fire, pitching Jeffress in two extremely high leverage situations in his first three appearances for the Royals. He did well in those two outings, working out of a jam with two runners on in the 12th inning versus Chicago (thanks to a pickoff) and then worked a scoreless 10th inning a day later, striking out two batters in the process. Yost didn’t call for him over the next six days, but when the bell finally rang in the bullpen, Jeffress responded with a couple of scoreless outings, including picking up a two-inning save in an appearance in Minnesota on April 13.

Then the trouble started.

He walked three batters, committed a throwing error on a pickoff throw and added a wild pitch for good measure in failing to protect a one run lead in the seventh against Cleveland on April 18. A week later he entered the game with two runners on, let them both score and added two more of his own for good measure. He steadied himself over his next four outings, throwing 4.2 innings of scoreless baseball where he allowed just one hit and no walks. You’d think he got back on track, but at that point, Yost put his young pitcher on the shelf for the next 10 days. He next appeared in the Vin Mazzaro debacle against the Indians where he was roughed up for two runs (and allowed all three runners he inherited from Mazzaro to score.) He made one more appearance where he walked three of the five batters he faced before he was farmed out to Omaha.

The struggles continued in Omaha where Jeffress posted a 6.8 BB/9 and had a 1.875 WHIP on his way to a 7.12 ERA. The Royals decided to drop him to Double-A and placed him in the rotation. Again, the results just weren’t there. He posted a 6.3 BB/9 in 32 innings with a 4.26 ERA. Most alarmingly, his strikeout rate experienced an extreme tumble down to 5.7 SO/9.

So, where do we go from here?

Jeffress is a two pitch pitcher – fastball and curve. And while the fastball is a heater in the true sense – it averaged 96.7 mph last year – he doesn’t miss a lot of bats. He had just a 9.9% whiff rate on his four seamer last year and overall, had a swing and a miss in just 7.6% of all swings, which was below league average. Also, he threw a first pitch strike in 48% of plate appearances. Again, that was below the league average which was just above 59%. That’s an enormous gap – on the wrong side of the average.

From the next chart, it’s easy to see how he walked a ton of batters. When he missed – he missed by quite a bit. Here’s every pitch Jeffress threw for the Royals last year.

Now, I’m no Bob McClure, but I’d have to think part of the problem with Jeffress is the lack of a repeatable delivery. His release point is all over the place. There’s the pitchers who are consistent in their release, those who vary their release (like Bruce Chen) and then there’s Jeffress.

That can’t be ideal.

Going forward, I don’t think the Royals know what to do about Jeffress. They’d like him to stick in KC as part of the bounty for Greinke, but the control issues aren’t going to disappear. Plus, he lacks the arsenal to start, so he’s going to have to make a living coming out of the bullpen. Given the arms Dayton Moore has collected for the Royals relief corps this winter, there’s no way Jeffress cracks the pen this spring. At this point, he’s organizational depth. From what we’ve seen, that’s probably his ceiling.