Corey Seager, the MLB's top prospect, wasn't expected to earn a promotion to the Los Angeles Dodgers in early September. However, an injury to shortstop Jimmy Rollins opened the door for the 21-year-old and he's making a case to snag the starting role from the longtime veteran.

Seager was initially the topic of rumors regarding a September call-up, but the Dodgers were planning on keeping him in the minors for the Triple-A playoffs to further his development. After all, he still had a bit to work on considering he witnessed a drop in his offensive numbers going from Double-A Fresno to Triple-A Oklahoma City.

But in 13 games with the Dodgers, the youngster is batting .426/.526/.617 with 9 runs scored, 1 home run, 8 RBIs and 2 stolen bases (57 plate appearances). He has also only struck out six times.

Earlier this week Mark Saxon of ESPNLosAngeles.com weighed in on the starting shortstop issue.

"The Dodgers have made great lengths to improve their defense. Seager isn't the equal of Jimmy Rollins when it comes to playing shortstop, but now that he has reached base in 25 of his 46 plate appearances, it's worth asking whether the Dodgers can afford to take his bat out of their lineup when Rollins returns from a bruised finger, perhaps as soon as Wednesday.

"All along, Dodgers manager Don Mattingly has said the job will be Rollins' when he's ready. After Monday's game, he changed his tone in a subtle, but perhaps meaningful, way. He said he didn't want to talk about it."

Rollins was used as a pinch runner on Friday and Saturday against the Arizona Diamondbacks. He has been taking grounders to get back in the groove and test out that injured knuckle, but after being evaluated on Wednesday, Mattingly told reporters the veteran would be out "several" more days.

So when he's healthy, will Rollins be back in the starting lineup?

"We'll see," manager Don Mattingly told Steve Bourbon of MLB.com. "We're going to have to give JT [Justin Turner] days off and we're going to put the best lineup out there ...

"Everything is always evolving. Right now we've got to get guys back healthy. There's plenty of playing time right now for Corey. 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."

If Turner gets some days off and Mattingly thinks Rollins should be the starter at short, that would at least keep Seager's bat in the lineup as he's capable of playing third base. The Dodgers were one of the worst offensive teams in baseball in the months of July and August, but they've improved in September. In 15 games the team has scored 68 runs compared to 104 runs in 27 games last month and 92 runs in 24 games the month prior.

Rollins was part of the reason the Dodgers were struggling offensively in July and August. The 36-year-old batted .240 with 19 runs scored, 6 home runs and 18 RBIs in 49 games over that span. July was Rollins' best month of the season, and he still batted just .234/.298/.481 with 12 runs scored, 4 home runs and 10 RBIs in 22 games.

However, the key argument here is poise on the defensive side of the ball, and Rollins has much more experience in that department than Seager.

Whatever the case, Mattingly will weigh each and every factor before making this decision. At this point, Seager at least looks like he'll make the Dodgers' postseason roster if he doesn't become the everyday starting shortstop once Rollins returns.

"All you have to is watch Corey Seager at the plate one time, especially against a left-handed pitcher," Tim Kurkjian said on the Baseball Tonight Podcast. "You realize how comfortable he is already as a major-league hitter, and therefore, for me at least, he has got to be on the playoff roster in one form or another."