Lance Lynn has a serious argument on the pitching side, and Yadier Molina has reached another level as a hitter, but over the last month a new competitor for breakout star has sprinted into the picture (and managed, in the meantime, to make people forget about a Colby Rasmus trade they still might disagree with in principle.) The trouble Jon Jay has had staying on the field will keep him from putting up the kind of full-season numbers, in 2012, that stick in people's minds, but he's gone from a league-average afterthought to one of the most popular players on the roster since the start of August.
Which is good news for him, since immediately before that he'd stopped hitting entirely. After returning from the disabled list in late June he looked every bit like a player who hadn't recovered from a shoulder injury. The .343 average he carried into mid-May fell steadily the moment he returned to the field, from .321 on July 1 to .303 on July 14 to .287 on July 31, after he went 1-5 in the Cardinals' 11-6 win over the Rockies.
Overall he'd hit just .231/.333/.298 across a month and a half, and it might have been attribution bias but he just looked like a guy with a bad shoulder, punchless and uncomfortable. He could run the bases—he stole six without being caught, despite managing just eight in 19 attempts in 2010 and 2011—and he could make his increasingly crowd-pleasing plays in the outfield, but he couldn't get a ball over the infielders' heads.
If the Cardinals had anybody else available, the fans might have clamored for him, but Shane Robinson's never inspired much clamoring and the Oscar Taveras clamor is not focused on his immediate call-up to the majors so much as how awesome he is, generally. So Jay went into August the center-fielder-by-default, a problem to be solved in the offseason.
Then, on August 1, he went 0-3 and grounded into two double plays. These arbitrary endpoints never quite work out.
But from there he went on an incredible tear, hitting .395/.471/.553 to date and showing off the uncanny ability to make solid contact that got him drafted in the first place, back when he was a college-aged tweener with uncertain power potential and a goofy swing.
The Jay we've seen this year—who even with the post-injury swoon now has an OBP of nearly .400—is at least momentarily a member of that rare club of great hitters with no power. His BAbip remains absurdly high (it's at .360 now) but he's also one walk away from matching last year's total in 170 fewer plate appearances.
Last year's Jon Jay hit for an empty .297. This one's doing a good Derek Jeter impression, hitting .300, drawing a lot of walks, running efficiently on the bases, and not playing an adequate shortstop.
It's certainly been crucial for the Cardinals in August, but it's just another unpredictable season for Jon Jay, who I found exceedingly difficult to project even when he was just hitting .290 and striking out too much. If you're looking for a reason to hope he can keep something like this up, I'll link again to this five-year-old example of the red baron's Jon Jay mancrush.