Part 2 in the series. See part 1 here. Part 3 is here.
Infielders! This is an area of strength, in my opinion, and there are a lot of guys I find interesting. Since SS and 2B seem to be very interchangeable in the Mariner system right now, I'm lumping them together. Ready, Begin!
Middle Infield, Or Bats Of Indeterminate Value
Obviously the discussion here begins with Nick Franklin. A high draft pick who played well at every stop until AAA, and then had a middling offensive season at 21 in the PCL, Franklin is still rated as a top 100 MLB prospect. His plate discipline and batting eye seem very solid for a guy his age at AAA, and he's shown flashes of a power bat for a middle IF guy. The biggest questions, for me, are a) can he stick at short? and b) should he stop switch-hitting?. As for a), I don't really care that much, He's not so dismal there that he couldn't play the position, and he'll never be Brendan Ryan. If his bat translates, they'll find a spot for him. B) may be more of an issue, but I'm willing to give him some more time on that front as well. Sample size is still too small against advanced pitching. Seems like a 2013 September callup to me, assuming he doesn't either explode or tank in Tacoma next season.
Franklin is far from the only interesting guy in this spot, though. Brad Miller and Stefen Romero both arrived in High Desert and just hit the tar out of the ball. Then they got bumped away from the ridiculous park factors in California and...just kept on hitting. Romero has actually hit BETTER in Jackson, if you can believe it. Miller dropped off just a tick but in a smaller sample, but he's also a year younger, plays short, and hits lefty. All said I'm higher on Miller but I think both have to figure into the Mariner's future plans. I think Ackley should be oiling up his outfield glove - when we get to the OF you'll see that those coffers aren't nearly as full.
A little lower down in the minors, there are still some interesting guys. Jack Marder is, to me, the biggest mystery in the Ms system. This is a guy they drafted as a catcher, and who his 209/360/295 his last year (draft-eligible sophomore) at Oregon in the Pac-10/12. He's played a little catcher and a lot of infield lately, and he's OPSd 873 and 1008 in back to back seasons at High Desert. I know, park factors! but still - his road OPS was 840 this season. That's a huge jump from a guy who couldn't hit college pitching. So while I don't necessarily believe in him as a prospect, he is definitely interesting.
There are some other guys, like Dan Paolini (is he a 2B? probably not), Chris Taylor (too soon to tell), and Martin Peguero (he's 18) but those first 3-4 guys are where the real interest is.
Next up, Third Base