According to Tom Krasovic of the UT and AZcentral.com.

Scribner is a 28th rounder who turned into a gem for the Diamondbacks’ full season A ball South Bend Silver Hawks.  The reliever struck out 52 batters in just 34 innings this year, walking only 8 without allowing a single home run.  His performance was impressive enough to make the Midwest League all-star team, and earned him a promotion to high A ball.

Though Scribner did not make either the Baseball Prospectus or Baseball America top 10s, it is not uncommon for pitching prospects to seemingly come out of nowhere.  See Garrison, Steve, whom the Padres received as a throw-in from the Scott Linebrink deal.

Scribner is a bit old at 22, so hopefully he’ll continue his fast track up the Padres’ system.  The team doesn’t have much need for a pinch hitter like Tony Clark this year, so I see the deal as something for nothing.  Bryan Myrow gives you everything Clark does, and now the team has a roster spot for Young or Bard and additional depth in low levels of the system.

Though if CY gets hurt again, we might have to walk Chris of the field by stacking people on top of each other.

EDIT 7/18: MB has a couple considerations I didn’t make.  He applies minor league park effects and and Scribner’s career numbers.  They’re definitely worth including.