On Tuesday, the third of the four Top 10 Oakland A's starting pitchers who were slated for AAA last winter made his rookie debut. In addition to rookies Trevor Cahill and Brett Anderson, Vin Mazzaro now makes the A's starting rotation 60% rookies with just the arrival of James Simmons to complete the circle. It was a victory with an alarming K:BB of .25 and a GB/FB of .29.
Just as I did with Jake Fox, I went and reviewed Baseball America's rankings and scouting reports on Mazzaro to see how he has developed over time. While he clearly improved, the reports are not so unambiguously glowing as to dispel my worries about his first start.
Additionally, I included the PECOTA comparables just for reference. In the 2009 Baseball Prospectus PECOTA, Mazzaro's comparables are Wally Whitehurst, Scott Chiamparino, Joe Johnson, and Josh Hall. He didn't merit a full write-up in 2008 Baseball Prospectus but was in "Line Outs" section with this small blurb: Despite pedestrian numbers, the A's still have high hopes for Vince Mazzaro, a raw power arm who gets plenty of groundballs with his sinker/slider combination.
The third high school pitchers the A's picked in the 2005 draft, Mazzaro was ahead of Jared Lansford [Ranked #15] to open 2006....but Mazzaro wrapped up his season in mid-August with an ERA north of 5.00 (he reached his inning limit), while Lansford earned a promotion [to Stockton]....has natural sink as well, with similar upper 80s/low 90s velocity. His best secondary pitch is a change-up....his curveball has its moments, particularly when he throws it with power and confidence. As the season proved, though, Mazzaro didn't always do that....Showing up on game day was enough against New Jersey high school players. But he learned that beating professionals requires better preparation, conditioning and mental toughness....
...good natural sink to his fastball...It's a heavy, 90-92 fastball that can touch 95 with late explosion through the zone. His best secondary option remains his change-up, but he struggled to command it as he rushed through the lower half of his delivery...and High A hitters pounced on his mistakes. His power breaking ball is below-average, though it shows flashes....everything is hard without much differential in his velocity....profiles better for the bullpen now until he shows consistent command of the breaking ball or feel for changing speeds. [Jared Lansford not in Top 30 due to shoulder tendinitis.]
...leading Texas League in ERA (1.90), earning TL pitcher of the year honors and a promotion to Triple-A [in 2008]. Hard sinker sits in low 90s and touches 95, generating groundballs. He pitches off his fastball, and he shows the ability to sink, run or cut it. His control got significantly better....showed a greater willingness to challenge hitters....improved slider has tight break and is an average pitch....still trying to find reliable off-speed offering...didn't throw his change-up much last season, though it took a step forward and could become an average offering...curveball more of a show me pitch. His mechanics are mostly sound, though he does throw slightly across his body...shouldn't have to rush Mazzaro. [Jared Lansford back in at #27.]