Despite a rash of injuries, the Dodgers are closing in on their third straight division title, a level of success unprecedented in the franchise's 132-year history. With 17 games to play, their magic number to clinch the NL West is down to 10, and their Baseball Prospectus Playoff Odds are up to 99.5%. The race is essentially over, but a very interesting situation is developing with regards to their shortstop position, where top prospect Corey Seager has flourished in Jimmy Rollins's absence, making the case for a changing of the guard that could strengthen the team as it vies for its first championship since 1988.

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The 36-year-old Rollins, whose 15-year run with the Phillies ended with a trade last December, has struggled in all facets of the game for nearly the entire season. At the plate, he's hit .220/.279/.355 with a 75 OPS+, across-the-board career worsts in every category but slugging percentage. Only in July, when he hit .234/.298/.481, has his OPS topped .655; only in September, when he's been limited to 24 PA, has his on-base percentage topped .298. If you go by pre- and post-All Star break splits, you can spot a modest uptick, from .213/.266/.338 to .233/.301/.386, but it's nothing to write home about.

It's not just Rollins's bat that's gone south, however. His base running has fallen off; the thief with 465 steals and a career 82% success rate is just 12-for-20 (60%) on the season, and where he was five runs above average per 162 games in terms of all of his base-path endeavors, he's two runs below this year. His glove work has been similarly subpar, with both Defensive Runs Saved and Ultimate Zone Rating pegging him as seven runs below average; via the former, he's been 0.4 wins below replacement level.

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Rollins played in 130 of the Dodgers' first 136 games, but a sprained right index finger has kept him out of the starting lineup since Sept. 6. The injury seemed so minor at the time that the team didn't even evaluate it for several days, but on Wednesday, manager Don Mattingly conceded that due to a setback while attempting to make throws, Rollins was several days away from playing the field. He has been limited to three pinch-running appearances since then, and while the finger hasn't bothered him while swinging the bat, Mattingly has yet to call on him given the team's swollen September roster.

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That opens the door for a further look at the 21-year-old Seager, the consensus No. 1 prospect via the Baseball America, Baseball Prospectus and ESPN midseason lists. The younger brother of Mariners third baseman Kyle Seager and the 18th pick of the 2012 draft out of a North Carolina high school, Seager was ranked as high as fifth on the major lists coming into the season on the heels of a combined .349/.402/.602 showing with 20 homers in 2014, split between the Dodgers' Class A Rancho Cucamonga and Double A Chattanooga affiliates. Seager returned to Double A to start this year (this time in Tulsa) but blazed through the league so quickly that he was promoted to Triple A Oklahoma City at the end of April. He had his ups and downs at the level but hit a respectable .278/.332/.451 with 13 homers before being promoted in early September.

At both minor-league stops, Seager dabbled at third base as well as shortstop, mainly to open up additional playing time options. At 6'4" and 215 pounds, he's huge for a shortstop, and talent evaluators have long been split on whether he'll have to move to the hot corner sooner rather than later. The evolving consensus, however, is that he can stick at his current position for the foreseeable future.

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​Seager made his major league debut on Sept. 3 against the Padres, going 2-for-4 with a double and a two-run single, and since then, he hasn't stopped hitting. He’s gone hitless in just two of his 13 games, one of which was a pinch-hitting appearance. Seven have featured multiple hits, including a 4-for-4 effort on Sept. 12 in Arizona that included two RBI singles and his first major league homer. In all, he's hit .426/.526/.617 in 57 PA for an impact that recalls the June 2013 blaze of Yasiel Puig, with less flash but far more calm, as evidenced by his nine walks. The lefty-swinging phenom is 7-for-20 against lefties and 13-for-27 with six extra-base hits against righties. As OKC-to-L.A. teammate Scott Schebler (who himself has done solid work to help offset Puig's absence due to a hamstring injury) told ESPN Los Angeles' Mark Saxon, "The beautiful thing about him is somehow he just rises to the occasion every time, it doesn't matter the expectations … for some reason he just somehow slows the game down every time."

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Admittedly, Seager has not faced a ton of great pitching yet, having played against only the Padres, Angels, Diamondbacks and Rockies; the Halos' Garrett Richards and Andrew Heaney are the only playoff-caliber starters he's faced. Still, he's collected his share of big hits, including an RBI single off Colorado's Jorge De La Rosa on Wednesday night that expanded the Dodgers' lead from 1–0 to 2–0, no small matter given the ongoing shakiness of their bullpen (they won). The team is 8–4 with him in the lineup—one missing Puig, Howie Kendrick and Kiké Hernandez (the last two of whom also have hamstring injuries), with Yasmani Grandal and Carl Crawford available only intermittently due to their own aches and pains, and regulars Adrian Gonzalez, Justin Turner and Andre Ethier scuffling. Powered by the unlikely combo of Seager, Aug. 31 acquisition Justin Ruggiano (.333/.375/.833 with three homers) and Schebler (.273/.385/.632), Los Angeles is 11–4 this month and has won 17 of 22 dating back to Aug. 23, taking seven straight series along the way.

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As Rollins continues to sit while Seager impresses, Mattingly and the analytically-inclined front office above him have adjusted their thinking as to the rookie's ongoing role. As of Sept. 12, the manager maintained that his veteran would return to the starting job, with Seager backing up both him and Turner (who can also cover second base). In the wake of Rollins’s setback, however, Mattingly hedged, acknowledging that the team's plans are a work in progress. Via MLB.com's Steve Bourbon:

"Everything is always evolving. Right now we've got to get guys back healthy. There's plenty of playing time right now for Corey," Mattingly said. "He doesn't need to worry about what's going forward, he just needs to play today. We don't need to worry about what's going forward, we need to win today."

Nobody this side of Barry Bonds maintains an 1.143 OPS for very long, and as Seager himself acknowledged, the league is likely to catch up with him sooner or later. Via Bourbon, he said after Monday night's win, "I imagine they'll have to start pitching me different pretty soon. Then I'll have to make some adjustments."

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Rollins is a veteran of 2,263 regular-season games as well as 46 postseason ones in five playoff runs with the Phillies. If he’s still injured, playing Seager is a no-brainer, but if Rollins does return to full health, it’s a delicate dance that Mattingly will have to do. Still, Rollins is running out of time to tune up for October, and as the manager and front office have made clear, this team—like president Andrew Friedman’s Rays and general manager Farhan Zaidi’s Athletics in recent years—loves its moving parts. No Dodgers position player—not Ethier, Turner, a less-than-100% Puig or a slumping Joc Pederson—is guaranteed full-time work; the team is platooning all over the place and going with the hot hands where appropriate to take advantage of the depth the front office has cultivated.

With a payroll in the neighborhood of $300 million, the pressure on the Dodgers to win is extreme, particularly after early exits at the hands of the Cardinals in the past two years. As they head for October, it’s far more likely that they’ll chase that elusive championship by putting their best configuration on the field on any given day, resumés be damned. Don’t be surprised if it’s Seager at shortstop when the chips are on the table, because increasingly, that looks like the right call.