Matt Carpenter, Cardinals
It indeed seems that Molina will win the votes of those inclined to support a Cardinal, but if Molina plays irregularly over the final month of the season and the Cards wind up winning the NL Central, then Carpenter could gain some traction. It would be justified, as he's played good defense in his first season as a second baseman, and he's batting .312/.381/.473 (136 OPS+) while leading the NL in hits and doubles.
Shin-Soo Choo, Reds
Like Miguel Cabrera last year, Choo figures to earn some points for his willingness to shift to a more premium position (center field, in his case). With the bat, his 2013 is going swimmingly: .285/.415/.466 with 19 homers from the leadoff spot and 253 times on base, which is good for second in the NL.
Joey Votto, Reds
There's some misguided criticism toward Votto regarding his RBI total, but a strong September in tandem with a Reds division title could put him in the mix. He leads the NL with a .430 OBP, and his OPS+ of 152 ranks fifth in the league.