Not every rookie will leave his mark on baseball like Aaron Judge and Cody Bellinger did a year ago, but each club has a prospect or prospects who should crack its big league roster in 2018. Below are MLB Pipeline's choices for the rookies who will make the biggest impact on each team in the National League East.
• Impact prospects: NL East | NL Central | NL West | AL East | AL Central | AL West
Atlanta: Ronald Acuna, OF (No. 1 on Braves' Top 30; No. 2 on Top 100)
Opening Day 2018: Triple-A Gwinnett
Right now, there is a lot of focus on the fact he didn't make the Opening Day roster. By the end of the year, no one is going to care, kind of like what happened with Kristopher Bryant in his rookie season. Acuna can and will impact the Braves' big league roster in a number of ways after shooting through three levels of the Minors and then winning Arizona Fall League MVP honors in 2017. A serious National League Rookie of the Year contender.

Miami: Lewis Brinson, OF (No. 1 on Marlins' Top 30; No. 27 on Top 100)
Opening Day 2018: Marlins
Acquired along with three other prospects in the offseason blockbuster trade for Christian Yelich, Brinson, a Florida native, already seems at home as part of the Marlins' organization. He's set to begin the season in the Major Leagues and could very well be Miami's most dynamic offensive player from Day One thanks to his impressive power and speed -- a combination that has long had scouts drooling over his ceiling.

New York: Chris Flexen, RHP (No. 9 on Mets' Top 30)
Opening Day 2018: Triple-A Las Vegas
Flexen was rushed to the big leagues from Double-A last year out of need and struggled, posting a 7.88 ERA in 48 innings. He pitched well, albeit briefly, in big league camp this spring and will go down to Triple-A to wait for another chance. There, he can work on trusting his stuff, something he did in the Minors, but not in New York last year. There is some pitching depth in this organization, but Mets fans know exactly how tenuous that can be. 
Philadelphia: J.P. Crawford, SS (No. 3 on Phillies' Top 30; No. 37 on Top 100)
Opening Day 2018: Phillies
An argument could be made for Crawford or Scott Kingery, who will be serving in a super-utility role. We'll give Crawford the nod since he'll be playing a premium position every day. Crawford shook off a rough start to the first half of 2017 in Triple-A to turn things around and earn his first big league callup, playing numerous positions over the season's final month. Now, his natural position of shortstop is all his, courtesy of the Freddy Galvis trade to San Diego. He has solid on-base skills and the bat is going to come, but more than anything in his rookie season, look for Crawford's defensive work to be his calling card.

Washington: Victor Robles, OF (No. 1 on Nationals' Top 30; No. 6 on Top 100)
Opening Day 2018: Triple-A Syracuse
Robles made the jump from Double-A to the Major Leagues at age 20 last September en route to a spot on Washington's postseason roster. He continued to impress with his dynamic, all-around tools this spring, but middling results combined with a healthy Nats outfield contingent will force him to Triple-A to begin the season. He shouldn't be there long, though, as there are few prospects capable of making an impact in as many ways as Robles can with his top-of-the-scale speed, hitting ability and defense.