That's Zep-Chin-Ski.  "Zep," as he's known, will be making his big-league debut tonight against the Tampa Bay Rays, making him the 5th Jay to do so thusfar this season (Romero, Cecil, Mills, and Ray being the first 4).  With the first of hopefully many big league starts on the horizon, let's take a look at the man they call Zep, who we have been loving on this site almost since the day he was drafted back in 2007.

First, would you believe that he's not the first big-leaguer professional baseball player with that surname?  Walter Rzepczynski pitched for a season for a minor-league affiliate of the Cubbies.

Anyway, Zep was drafted by the Blue Jays in the 5th round of the 2007 draft out of University of California - Riverside, alma mater of Troy Percival and current Jays farmhand Bill Murphy.  Like most collegiate draftees, Zep was sent to Auburn for short season A ball and he did a great job in his 11 appearances (7 of which were starts), helping the Doubledays to claim the New York-Penn League championship.  Zep struck out more than a batter/inning and kept baserunners to a bare minimum.  2008 saw Zep spend the entire season in Lansing, but it wasn't because of stagnant performance.  Anything but, as the lefty struck out almost three batters for every one he walked and again notched more than a K/inning over his 22 starts that season.  It was an impressive campaign and would certainly have seen Zep promoted but for the time he lost early in the season to a broken hand.  2009 saw Zep skip Dunedin and begin right in AA, where he was excellent for 14 starts before earning a promotion.  Zep kept mowing batters down, although his walk rate ticked up a drop, and continued to be ridiculously stingy in allowing home runs.  That he was as successful as he was despite an unlucky .381 BABIP against him just shows you how good he has been this season.  Anyway, Zep didn't slow down at all when he was promoted, putting together two fantastic starts for Las Vegas before earning his callup.  It's a quick callup for Zep, considering he has only a half season pitching at AA or above, but he has risen to every challenge so far. 

How does he do it?  Well, he's not getting those K's by blowing batters away, though Zep does feature a low-90s fastball with heavy downward action.  That pitch is critical to Zep's ability to get hitters out - he induces a ton of groundballs, which, coupled with his ability to strike batters out, is a formidable skillset for a young lefthanded pitcher (or any pitcher for that matter).  He compliments his sinker with a very nice changeup, also with excellent downward action, a pitch that is key to his success against right-handed hitters, as well as a very nice slider and a low-80s curve that's more of a show pitch.  Here's Jays minor-league pitching coordinator Dane Johnson on Zep:

His stuff is every bit as good as, if not in some ways better than Cecil.  I am taking nothing away from Brett but Zep is as accomplished. Zep does have electric stuff, it moves and it’s hard. And it moves down, he has sink on the two-seamer, he has a terrific slider and very good movement on the change-up and sometimes it is hard to keep his stuff on the plate it is moving so much. He can embarrass hitters with his stuff. He needs to pound the zone at a higher clip. He is doing fine he just needs to work on getting into the seventh inning every night rather than five and two thirds, he needs to get those extra five or six outs.

I love that quote because Johnson hits on what makes Zep a good prospect and what he needs to do to make himself a good major-league pitcher - namely, go deeper into games (he's only averaged about 5 and a third innings per start in his minor-league career, and major-league hitters will make you work) and throw strikes.  Of course those things are linked.  Not walking folks (he was walking too many at AA this season, over 4/9 innings) is crucial to his major league success because although Zep is an excellent groundballer, there's no way he can keep up the crazy home run numbers he's had in the minors - no one can.

Zep entered this season as a well-regarded prospect (we ranked him 11) but still a bit of a question mark since he had only tested his stuff against A-ball hitters and was old for the level.  This season, he has erased those question marks and should be regarded as a legitimate candidate to pitch in a major-league rotation regularly as early as next season.  His ceiling might be as more of a mid-rotation starter, but he has the talent and pitching ability to make a positive contribution for years to come.  He might be an emergency injury replacement for this start, but Jays fans will be treated to a pitcher who is a very legitimate part of the team's future plans.