A few years back, Sean O’Sullivan was somebody.

As a 19 year old in the Midwest League, the rotund righty threw 158 innings, allowed just 136 hits, walked only 40 and struck out 125 on his way to a 2.22 ERA (3.04 FIP).   Baseball America named him the fifth best prospect in the Angels’ system.

The following year, O’Sullivan pitched the same number of innings, walked ten more batters, struck out 14 less and, thanks in no small part to pitching in the hitter’s Shangra-La known as the California League, was tagged for a 4.73 ERA (albeit with a still decent 3.61 FIP).  For those of you who remember the days of Royals’ prospects spending the summer in High Desert, you will note that overall it was far from a disaster for O’Sullivan.

Then along came 2009, when the Angels decided to give Sean a whirlwind tour of America.   He started three games in AA: giving up one run over six innings in his debut and then a combined 10 runs over 12 innings in his next two.   That was apparently enough for the Angels to send him to AAA, where O’Sullivan made nine starts with varying degrees of success before earning a promotion to the bigs.

In his debut against the Giants, O’Sullivan allowed just one run over seven innings of work.   The Angels gave Sean three more starts (two okay, one not so hot) before returning him to AAA before the All-Star Break.  O’Sullivan was lit up in a single AAA start on July 9th and did not pitch again until being recalled to face the Royals on July 21st, holding our boys to two runs over five plus innings and getting the win.

Returned to AAA immediately thereafter, O’Sullivan then threw a complete game no-hitter on July 28th (facing just one over the minimum).   Quite obviously, that was enough to get him back to the majors where Sean was basically awful in four August starts.   That earned him a trip back to AAA for one start and one relief appearance, followed by three more big league outings in September (one start, two relief appearances).

Overall, 2009 saw Sean O’Sullivan post ERA’s of well over five at each of the three levels he threw at.  His strikeouts went from 6.75/9 in AA to 5.05 in the majors and his home run rate went from 0.48/9 in AA to 1.17/9 in AAA to 2.09 in the majors.   The best thing about O’Sullivan’s 2009 was that he managed to grind out 138 total innings.

Back in AAA to start 2010, SOS started 13 consecutive games and went six or more innings in nine of those contests.   He was called up to Anaheim in late mid-June to make four relief appearances (allowing just one run), returned to AAA for two starts in July and then back up to pitch in Yankee Stadium on July 20th.  He held the Yankees to two runs over six innings to get the Angels a win.

As you know, O’Sulllivan and Will Smith were then traded to the Royals for Alberto Callaspo (whose lack of ability to act as a civilized human being outside the white lines outweighed his ability at the plate) and Sean found himself in a different uniform facing that same New York team in the same stadium just five days later.  He was tagged for five runs in five innings in what would be a very representative start for him over the next eight turns through the rotation.  

Only in late September would O’Sullivan show much as he ‘Kyle Davied’ his way through three straight six inning starts at the end of the year:  allowing two runs, then one, then none.   Even with those three good starts, O’Sullivan ended up with a combined big league 5.49 ERA (4.98 xFIP) and struck out just 4.63/9, while walking 3.3/9 and allowing home runs at the rate of 1.61/9.    

In a surprise move, the Royals broke camp in 2011 with O’Sullivan in the bullpen and Vin Mazzaro in AAA waiting for the time when Kansas City would need a fifth starter.   O’Sullivan allowed five runs in four innings over two relief appearances, but thanks to Mazzaro walking seven in his AAA tune-up start, Sean was given the fifth starter spot on April 16th and responded by throwing five shutout innings against Seattle.

Following that, O’Sullivan allowed just two runs over six innings against Cleveland, only one earned run against Minnesota the next time out (although he walked 7 in 6 innings) and then only three runs over eight innings against Oakland despite not striking out a batter the entire game. 

Smoke and mirrors?   Apparently.   In O’Sullivan’s next five starts he allowed 4, 6, 7, 10 and 7 runs and was thankfully banished to AAA until making a September 27th start against Minnesota where he allowed six runs in five innings.

By the time 2011 was said and done, Sean O’Sullivan had thrown 58 big league innings, being tagged for 78 hits (10 homers), while walking four batters per nine innings and striking them out at a rate below THREE.   Earned run average seldom gives us a truly accurate picture of a pitcher, but Sean’s 7.26 seems pretty much on target to me.   

While O’Sullivan had a nice run in AAA (4.22 ERA, 6.6k/9, 1.9 BB/9) he is a pitcher who, against big league hitting, struggles to throw strikes and can’t keep the ball in the park when he does.  

On paper, you have a pitcher who averages between 91 and 92 mph on his fastball, has a sometimes pretty good curve and can offer a change-up in the mid-seventies, but none of that translates into success.   Without one really good pitch or the ability to consistently throw a couple of decent pitches for strikes, O’Sullivan does not really strike this writer as a relief option (particularly given the number of better options the Royals currently possess) and he certainly is well down in the pecking order when it comes to getting another shot at starting.

For 2012, I imagine O’Sullivan will be part of the Omaha starting rotation where he might see some major league action if the Royals need someone to step in for a couple of weeks and don’t want to disturb the progress of more prized prospects.  When it comes to the long-term, it is tough to see where O’Sullivan fits in and, honestly, it is probably for the best that he does not.