Should Andy Dirks be Replaced in LF?

Andy Dirks has been disappointing this year, hitting .238/..291/.338 before today's game.  And he's been especially awful his last 17 games, hitting .183/.216/.197 from May 26th - June 17th.  This is after hitting .322/.370/.487 in 344 PA in 2012, leading many people to believe he can be an above-average everyday left fielder.  He hit .274/.354/.397 against left-handed pitching, proving that he didn't need a platoon partner.  However, he has failed to sustain his .365 BABIP, which means that 2012 couldn't been a fluke all around.  He's only hitting left-handers at a .182/.250/.273 clip so far this year.  

James Schmehl at MLive recently posed the question that Andy Dirks' job could be in jeopardy when the Tigers need a starting pitcher on Thursday.  When Anibal Sanchez went on the disabled list, instead of recalling a pitcher right away, the Tigers elected to call up Avisail Garcia again.  This is indication that the Tigers might at least be thinking about sending Dirks down to AAA; they currently have 11 pitchers on their roster and Leyland normally keeps 12.  If Andy Dirks does become the odd man out, there are 3 viable candidates to take his place, Matt Tuiasosopo, Avisail Garcia and Nick Castellanos - all have their positives and negatives.
     

Matt Tuiasosopo:

Why he should be the everyday LF:  He's been hitting excellent this year, .333/.465/.551 before today's game.  He's been hitting for average, power (.217 ISO), and patience (17.4% BB rate).  His 183 wRC+ demands more playing time.    

Why he shouldn't be the everyday LF: Before this year, Tuiasosopo was a career .176/.234/.306 hitter and hadn't seen ML pitching since 2010.  At age 27 it's hard to believe that he's all of a sudden figured everything out.  Some of his stats do suggest a regression.  His BABIP is at an unsustainable .417 as it's hard to believe he can keep a 29.4% LD rate.  His HR/FB ratio is at 21.4% but his career rate is only 13.1%.

Avisail Garcia:

Why he should be the everyday LF:  He's one of the Tigers top prospects that has some success against ML pitching.  In his limited time in the majors, he's hit .296/.339/.391 while adding power in 2013 with a batting line of .279/.315/.441 with 2 HR.  In his first 10 games at AAA, he hit .467/.489/.578, suggesting that he has nothing more to learn in the minors.  The Tigers keep adding him to the roster whenever there's a spot open, even though Leyland hasn't played him as much as most people would like.

Why he shouldn't be the everyday LF:  There is one stat that stands out that needs improving with Garcia - his walk rate.  It's at 5.5% so far this year and it was regularly in the 3-4% range all through the minors.  At 22 years old, he needs to play everyday as he continues to mature as a hitter and Leyland has been criticized for playing Don Kelly more over Garcia.  If Garcia isn't getting the playing time in the majors, then he needs to get them in the minors. 

Nick Castellanos:

Why he should be the everyday LF: He's the Tigers #1 prospect and he's been playing like one so far this year.   He's hitting .293/.366/.477 so far this year at AAA and he's been especially great lately.  After hitting .237/.284/.391 in his first 169 PA, he's hit .359/.455/.580 in his last 156 PA.  He's showing that he has nothing more to prove in AAA.

Why he shouldn't be the everyday LF:  He has no ML experience.  That could be dangerous, giving a rookie an everyday role in the middle of a playoff race who has been known to struggle after getting promoted after every step in the minors.  The Tigers might not want to take the risk of having him lose confidence and like Garcia, Castellanos should be getting everyday playing time as he matures as a hitter.

It's very likely that the Tigers will send down Avisail Garcia to make room for Jose Alvarez on Thursday.  At the very least, Dirks might lose some playing time to Matt Tuiasosopo without him actually taking over the position.  As bad as Dirks has been on the hitting side, advanced stats show that Dirks has been excellent on defense so far this year as Patrick O'Kennedy of Bless You Boys has pointed out.  This has given Dirks a 0.8 fWAR and a 0.9 rWAR, which means he's on pace for about a 1.5 WAR.  While that's below average, it doesn't really warrant a trip to AAA either.  

Besides, the Tigers have more pressing needs, such as the bullpen and the Jose Valverde situation.  

Update:  Avisail Garica has indeed been sent back to AAA to make room for Jose Alvarez.