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Former Athletic Jack Hannahan will be counted on for his glove skills while Adrian Beltre is out. His contributions could be key for Seattle if they are to make a playoff push.

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Acting quickly to supplement an infield gutted by an injury (Adrian Beltre) and incompetence (Yuniesky Betancourt, Ronny Cedeno, Jose Lopez, and Chris Woodward), Seattle GM Jack Zduriencik acquired slick fielding 3B Jack Hannahan from division rival Oakland for AA pitcher Justin Souza.  Hannahan, with a .264 wOBA, has had a rough year with the bat so far, and as a result spent the last two weeks with AAA Sacramento.   Hannahan's 2008 wOBA of .289 did not leave Oakland expecting him to be a major contributor to the lineup.  Still, even the most pessimistic of A's fans would not have expected a line of .193/.278/.303.  Hannahan's terrible BABIP of .268 is likely influencing his struggles, but a declining ISO (.146 in 2007, .124 in 2008, .109 in 2009) is disconcerting.

However, despite Hannhan's struggles, his glove has remained remarkable.  Through 218 games at 3B, Hannahan has a UZR of +17.7, or a UZR/150 of +14.2.  This compares favorably with such stars at 3B as Adrian Beltre and Evan Longoria.  Of course, Hannahan's bat does not equal either of those by a long shot, but even with Hannahan's .264 wOBA, his 2009 UZR of +6.4 has him as a roughly average player so far.

Justin Souza has had a very solid year so far with the AA West Tennesee Diamond Jaxx.  Although West Tenn is a pitcher friendly team, Souza's 2.05 BB/9 is very encouraging, and a 7.06 K/9 is nothing to sneeze at either.  However, Souza has been lucky with his line drive rate, giving up 21% line drives and only surrendering a .297 BABIP.  Souza could have the potential to be a back-end starter or a solid bullpen piece, but it's really hard to say at this point.

Like many of the players we've seen dealt so far this trade season, the 29 year old Hannahan is too old to really expect any major strides.  Still, going forward, Hannahan's successful 2007 season (.352 wOBA in 41 games) and minor league track record (.380 and .424 OBP in 2 years at AAA) show some promise.  Hannahan fits the Athletics mold - he's not a free swinger and he sports a good career walk rate of 11.3%.  ZiPS projects Hannahan's wOBA to rise up to .310 given his solid track record. 

Given the uncertainty in the projection, we can expect the value of Hannahan's bat  over 75 games, roughly what could be expected if Hannahan is a regular for the Mariners, to be somewhere in the -7 to -2 range.   Hannahan's 6.8 UZR is probably a bit much to expect out of him over another 50 game sample, but he is very solid., he would probably be worth +3 to +7 with the glove.  With the +1.25 positional adjustment and roughly 10 run replacement adjustment, Hannahan's value for the rest of the way comes out in the range of +0.7 wins on the low end to +1.6 wins on the very high end. 

We must consider, however, with this calculation, the player that Hannahan is replacing in the Mariners infield, Chris Woodward.  Woodward, in a very limited sample, is a decent fielder at 3rd, showcasing a +4 UZR in 450 innings.  Looking at his track record at other positions, he has a -4.3 UZR/150 in 2500 innings at SS and a +1.2 UZR/150 in 540 2B innings.  With this in mind, Woodward is probably more of a -2 to +3 defender at 3B, and is far eclipsed by Hannahan in this respect.  Combine that with ZiPS projecting a meager .275 wOBA for the 33 year old (career .293), and Hannahan is probably replacing a below replacement level player over the rest of the season.  Bearing this in mind, this acquisition could have a huge impact on a very tight AL West race, with Hannahan adding possibly 1 to 2 wins to the Mariners from here on out.  Given Hannahan's pre-arbitration status as well, this move gives the Mariners a good, cheap, bench option past 2009 and possibly a starter for 2010, if his hitting returns to 2007 form.

Update via @gbakermariners: Hannahan batting 8th for Mariners tonight.