Prospect Retro: David Aardsma

Prospect Retro: David Aardsma

Pitchers who throw hard get plenty of chances, even if they aren't particularly successful. Many times an ineffective pitcher with a good arm remains just that: ineffective. However, occasionally a "good arm/ bad result" guy will figure something out and blossom. Case in point: Mariners closer David Aardsma.

David Aardsma was the closer for Rice University, winners of the College World Series, back in 2003. He broke Matt Anderson's career and season saves records  for the Owls, using a 94-98 MPH fastball, an erratic-but-promising breaking ball, and a good changeup to post a 2.97 ERA with 12 saves and a 46/19 K/BB ratio in 58 innings, allowing 47 hits. Rice coaches had him using a knuckle-curve. Scouts loved his arm and projected him as a big-league closer, but concerns about his command and stressful mechanics hurt his stock just a bit on draft day, pushing him down to 22^nd overall after some talk that he could go in the top ten. He signed without much delay and went to San Jose in the California League, where he picked up eight more saves, posting a 1.96 ERA with a 28/7 K/BB in 18 innings. I gave him a Grade B in my 2004 book, writing that he would move quickly if his command held up.

The Giants were aggressive with Aardsma in 2004, assigning him to Triple-A Fresno. He held his own in the Pacific Coast League, picking up 11 saves, posting a 3.09 ERA, with a 53/29 K/BB in 55 innings and 46 hits allowed. The walks were a little high, but considering the jump in competition it was a good year. He continued to top out at 98 MPH on his best days, but his average velocity slipped downward into the 91-94 MPH range. His changeup was decent, but he dropped the knuckle-curve he used at Rice in favor of a more traditional slider, which gave problems. He got knocked around in a major league trial, giving up 20 hits in 10.2 innings, showing poor command with a 5/10 K/BB, leading to a 6.75 ERA.I gave him another Grade B in the 2005 book.

After a rough spring training, the Giants sent Aardsma back one level to being 2005, using him as a starter at Double-A Norwich to give him more innings to work on his breaking ball. The results looked okay on paper: he went 6-2 with a 2.93 ERA and a 30/13 K/BB in 46 innings, but his strikeout rate went way down and his velocity was subpar, just 89-92 MPH. He didn't show much improvement with the slider, and the Giants ended up trading him to the Cubs in May. Sent to Double-A West Tennessee by Chicago, he moved back to the bullpen but his velocity did not return, still just 89-92 MPH and even lower at times. He posted a 3.91 ERA and a 43/32 K/BB in 51 innings, with 48 hits allowed. By the end of the season, his stock had dropped so much that he didn't even rank in Chicago's Top 30 prospects according to Baseball America. He still had command problems, the slider was still shaky, and he no longer threw very hard. A lot of people felt he was trying to pitch through an injury, that his mechanics and the whole "Rice pitchers get hurt" thing was catching up with him. I put him in my book, but with a Grade C rating.

Aardsma looked better in spring training '06, earning a spot with Triple-A Iowa. He pitched better, with a 3.22 ERA and a 36/15 K/BB in 36 innings, with 31 hits allowed, collecting eight saves. I saw him pitch twice, and both times he was throwing 89-92 MPH with an okay-but-not-great breaking ball. The Cubs gave him a shot in the bullpen when they needed an arm, and he wasn't bad, posting a 4.08 ERA with a 49/28 K/BB in 53 innings, allowing 41 hits. His command wasn't reliable enough for him to be used as a closer, but it looked like he could be a credible middle man.

Aardsma shuttled across town to the White Sox for 2007, splitting the season between Triple-A Charlotte (4.33 ERA, 45/11 K/BB in 35 innings, 15 saves) and the White Sox (6.40 ERA, 36/17 K/BB in 32 innings, 39 hits). Although his ERA with the White Sox was ugly, there were signs of progress: his K/IP was strong, and his velocity was coming back, averaging 94.8 MPH in his major league time.  His FIP was much better than his ERA at 4.29.  He began to use a new pitch, a split-fingered fastball.

Despite the flashes of promise, the White Sox weren't impressed and designated him for assignment. The Red Sox gave him a shot in '08, and while he fanned 49 in 49 innings and continued throwing 93-94 MPH, he walked 35 guys and posted a 5.55 ERA. The slider remained mediocre, the new splitter was erratic, and command was an obvious problem. Entering 2009, Aardsma was definitely in the "good arm but disappointing category." He got designated for assignment again.

The Mariners gave him a shot last year and he took rapid advantage, seizing the closer role and posting 38 saves with a 2.52 ERA and a 80/34 K/BB in 71 innings, with 49 hits allowed. Compared to '08 and '07, he showed much improved control while maintaining a strong strikeout rate. Interestingly, his average velocity dropped slightly to 94 MPH. He also used his slider much less: he threw it just 6.3% of the time, compared to 13% of the time in '08 and 23% of the time in '07. He completely stopped throwing his standard changeup, using the split-fingered fastball instead. The rations have remained about the same this year: 82% fastballs, 9% sliders, 9% splitters.  

What has made the difference for Aarsdma? I see four factors: 1) regaining much (though not all) of the velocity he lost in 2005/2006;  2) better overall control; 3) development of the splitter to go with the fastball and slider; 4) willingness to use the fastball more often.

In college, scouts projected Aardsma as a major league closer. He got there, but the route was roundabout.