The best rookie on every MLB team in 2018

The soon-to-be 34-year-old Hirano comes over from Japan after recording 156 career saves. He will challenge Archie Bradley for closer duty in spring training after posting a 2.67 ERA in 58 appearances for the Orix Buffaloes last season.

Arguably the top prospect in baseball, Acuna won't be far away from Atlanta if he fails to break camp with the team. He hit .325-21-82 with 44 steals in 612 plate appearances between three levels last season at age 19.

Hays was the first player from the 2016 draft to arrive to the majors despite being drafted in the third round. He hit .329-32-95 between High-A and Double-A last season and likely has a starting job waiting for him entering the season.

Boston's farm system is in rebuilding mode, so Travis isn't the typical elite prospect on the cusp of the majors. He still has a chance to be a solid major leaguer and hit .270-6-24 in 82 games at Triple-A Pawtucket last season.

Caratini took a huge step forward with his bat at Triple-A Iowa last season and also got some work in Chicago. He hit .342-10-61 with a .951 OPS in only 326 plate appearances for Iowa. He's set to back up Willson Contreras this season.

Acquired from Boston last offseason for Chris Sale, Kopech can touch 100 miles per hour on the radar gun. He showed his huge upside with his performance last season between Double- and Triple-A with a 2.88 ERA and 172 strikeouts in 134.1 innings. He still needs to work on his control before he's truly ready for the majors.

Cincinnati has an impressive list of prospects graduating to the majors this season, including Winker, starting pitcher Tyler Mahle and eventually third baseman Nick Senzel. Winker looked terrific in his MLB debut last season with a .904 OPS in 137 plate appearances, and he's been an on-base machine in the minors with a .398 career on-base percentage.

Mejia had a cup of coffee in September and shouldn't have a problem starting for Cleveland if he looks ready in spring training. The elite prospect hit .297-14-52 with an .835 OPS at Double-A Akron last season.

Colorado has yet to bring back Mark Reynolds or sign another first baseman, so McMahon is penciled in as the team's first baseman. He hit a spectacular .355-20-88 with a .986 OPS between Double- and Triple-A last season.

Detroit's rebuild was desperately needed just by looking at the lack of upper minors talent. Stewart does have a chance to be a major league regular and contributor in the second half of this season. He hit .256-28-86 at Double-A Erie last season.

Paulino missed half of last season due to a PED suspension, but he still made six starts with Houston. A dominant minor league pitcher in the past, Paulino had a 2.00 ERA and 10.6 K/9 between three levels in 2016. He could develop into a key long reliever this season.

With K.C.'s failure to re-sign Eric Hosmer, Dozier will compete for the starting first base job. He missed most of last season due to injury but hit .296-23-75 between Double- and Triple-A in 2016.

Possibly the most hyped foreign player ever, Ohtani signed with the Angels in the offseason. He's set to be their ace at age 23 and will also get a chance to hit after the team traded C.J. Cron. He will have quite a time matching the expectations of a modern-day Babe Ruth.

A first-round pick in 2015, Buehler will compete for a roster spot in spring training. The hard-throwing right-hander can reach the upper-90s with excellent sink on his fastball, and he had a 3.35 ERA and 12.7 K/9 between three levels in the minors last year.

Acquired from the Marlins for Christian Yelich, Brinson is set to start in center field for Miami. He struggled during his MLB debut but hit .331-13-48 with 11 steals in 340 plate appearances at Triple-A Colorado Springs last season.

Woodruff has a shot to be Milwaukee's fifth starter after what he showed in the majors last season. He had a 4.81 ERA in eight starts but showed excellent stuff. He also had a 4.31 ERA in 17 minor league starts, spending most of his time at hitter-friendly Triple-A Colorado Springs.

The Twins' youth movement continues, and Gonsalves isn't far away. The lefty had a 3.27 ERA and 3.81 K/BB ratio in 110 innings between Double- and Triple-A last season. While he's unlikely to break camp with the Twins, he could be a key piece of the rotation by midseason.

Cecchini is a potential utilityman in a very thin Mets farm system. He hit .267/.329/.380 at Triple-A Las Vegas last season.

Torres is coming off Tommy John surgery but could break camp as the Yankees' regular second baseman. He hit .287-7-34 with an .863 OPS in 235 plate appearances between Double- and Triple-A last season. A natural shortstop, he's also outstanding defensively.

Fowler suffered an ugly knee injury during his MLB debut, but he's the front-runner to win the center field job for the A's entering spring training. Acquired in the Sonny Gray trade, Fowler hit .293-13-43 with 13 steals in 70 games at Triple-A Scranton/Wilkes-Barre before getting hurt.

Philadelphia is set to introduce an impressive crop of prospects this season that includes Kingery, J.P. Crawford and Jorge Alfaro. A former second-round pick, Kingery had a breakout 2017 season by hitting .304-26-65 with 29 steals between Double- and Triple-A. He could spark the Phils to trade Cesar Hernandez with a good spring.

The main criticism for Moran in the minors was his lack of power — until last season. The former sixth overall draft choice in 2013 hit .308-18-63 in 338 plate appearances at Triple-A Fresno and has a great chance to start at third base for the Pirates.

Cordero will have a difficult time finding at-bats early in the season for San Diego, but he has plenty of potential. He hit .326-17-64 with 15 steals and a .972 OPS at hitter-friendly Triple-A El Paso last season. Cordero is also coming off a great Dominican Winter League showing.

San Fran's best hitting prospect, Shaw hit .292-24-79 between Double- and Triple-A last season. He also hit 21 home runs in 2016. The Giants are working him out in the outfield, and he could be a regular by the All-Star break.

Vogelbach's attempt to solidify the starting first base job last season was a disappointment, but he could get another shot at gaining momentum early this year after Ryon Healy had hand surgery. The big first baseman did produce an .844 OPS at Triple-A last season.

Coming off of Tommy John surgery, the Cardinals are aiming to have Reyes back in early May. He was terrific in his MLB debut in 2016, posting a 1.57 ERA with 52 strikeouts in 46 innings. It's unclear what role he will serve this year, but starting and closing are both possibilities.

Tampa Bay has had an offseason fire sale, and Adames will be one of several rookies to make an impact i 2018. He played all of last season at Triple-A Durham and turned 22 in September. Adames hit .277-10-62, and his defensive ability should fit well if and when the Rays move on from Adeiny Hechavarria.

Traded from the Dodgers to Rangers for Yu Darvish last season, Calhoun is likely to start in the outfield on Opening Day. He had a terrific year at Triple-A in 2017, hitting .300-31-93. Calhoun also has uncommon plate discipline for a power hitter, fanning only 61 times in 534 plate appearances.

Jays fans are excited about Vladimir Guerrero Jr. and Bo Bichette in the long term, but those prodigious hitters probably won't get a look this year. Alford does have a chance to carve out a role after hitting .299-5-26 with 19 steals in 77 games between three minor league levels last season.

Washington has had a quiet offseason in the outfield, likely because Robles is close. The top prospect hit .300-10-47 with 27 steals between High-A and Double-A last season. He could be a big factor during the second half of the season.