As the best position prospects to make Opening Day rosters, White Sox outfielder Luis Robert and Nationals third baseman Carter Kieboom are favorites to win Rookie of the Year honors. However, beginning the season in the big leagues is not a prerequisite for taking home the rookie hardware.

Yordan Alvarez, the 2019 American League ROY, didn't join the Astros until two months of the season had passed. The Braves waited three weeks before calling up 2018 National League ROY Ronald Acuña Jr.

With that in mind, we've identified a potential impact callup for each of the 30 teams. Don't be surprised if the list includes one of the 2020 Rookies of the Year.

AMERICAN LEAGUE EAST

Blue Jays: Simeon Woods Richardson, RHP (No. 3/MLB No. 98)
The Mets’ second-round pick from the 2018 Draft pitched better than his numbers suggest at Class A Columbia, and then made six impressive starts for Class A Advanced Dunedin after joining the Blue Jays in the Marcus Stroman Trade Deadline deal. The young righty features a plus fastball-curveball combo, a promising changeup and an advanced overall feel for his craft, all of which made a strong impression on club officials during Summer Camp.

Orioles: Ryan Mountcastle, 1B/OF (No. 4/MLB No. 94)
It was surprising that Mountcastle wasn’t part of the Orioles’ Summer Camp from the get-go, but he was added later. After a strong 2019 season in Triple-A, his bat is just about ready to contribute. He’s limited defensively, but he can play left field or first base, so keep an eye on if Chris Davis bounces back this year.

Rays: Brendan McKay, LHP/DH (No. 2/MLB No. 15)
McKay’s success between Double-A and Triple-A -- 1.10 ERA, 0.81 WHIP, 102/18 K/BB in 73 2/3 IP -- last season earned him his first big league callup in June, and the former No. 4 overall pick (2017) went on to make the Rays’ postseason roster after tossing 49 solid innings (11 starts). He’s not on Tampa Bay’s Opening Day roster due to undisclosed reasons, but can step into any number of roles on the team’s staff once active.

Red Sox: Bobby Dalbec, 3B/1B (No. 3)
Dalbec ranks sixth in the Minors with 59 homers over the last two seasons and also plays quality defense at third base. But the 2016 fourth-rounder out of Arizona is blocked by Rafael Devers at third base and currently sits behind Michael Chavis in the pecking order for righty at-bats at first base.

Yankees: Clarke Schmidt, RHP (No. 2/MLB No. 88)
A first-round pick from South Carolina in 2017 just a month after having Tommy John surgery, Schmidt has made a full recovery and looked great down the stretch last season in Double-A and again in Summer Camp. Armed with three pitches that grade as plus at their best, he could play a large role in New York's aging rotation.

AMERICAN LEAGUE CENTRAL

Indians: Logan Allen, LHP (No. 11)
Cleveland has just two left-handed pitchers on its Opening Day roster, and Allen could serve as both a multi-inning reliever and depth starter. Acquired from the Padres in the three-team Trevor Bauer trade last July, he can throw strikes with four different pitches, the best of which is a tumbling changeup.

Royals: Brady Singer, RHP (No. 2/MLB No. 59)
The 2018 first-rounder was as good as advertised during his first full season, reaching and pitching well in Double-A. His three-pitch mix and excellent command was on display during both Spring Training and Summer Camp, and he’s expected to make his big league debut Saturday, in Game 2 against Cleveland.

Tigers: Casey Mize, RHP (No. 1/MLB No. 7)
Mize was as dominant as any hurler in the Minors during the first part of the season and fired a no-hitter in his Double-A Erie debut, but issues with his right shoulder landed the 2018 No. 1 overall pick on the injured list in June, and he was inconsistent upon returning before being shut down for the season in mid-August. As long as he’s healthy, Mize, with three plus pitches and exceptional feel for his craft, should soon headline an exciting young Tigers staff.

Twins: Jhoan Duran, RHP (No. 5)
While Duran has only made seven starts above Class A, his electric stuff could almost certainly get big league hitters out and he made a very good impression during Summer Camp. His fastball touches triple-digits and he’s got a solid breaking ball, but it’s his splitter-sinker hybrid that’s completely unhittable. And who doesn’t want to hear a play-by-play announcer say, “splinker” on air?

White Sox: Nick Madrigal, 2B (No. 4/MLB No. 40)
With Chicago looking to return to the ranks of contenders, it shouldn't wait too long before handing its second-base job to Madrigal, the No. 4 overall pick in the 2018 Draft. The Oregon State product is the best contact hitter in the Minors and also possesses plus speed and defensive ability.

AMERICAN LEAGUE WEST

A’s: A.J. Puk, LHP (No. 3/MLB No. 60)
This involves some wishful thinking that the big left-hander’s shoulder bounces back and he can return to health. He’s officially on the injured list right now. If he responds well and shows he can throw at full capacity, he has the stuff to help out in the rotation, though the combination of health and command issues could mean a bullpen role, at least for now.

Angels: Jo Adell, OF (No. 1/MLB No. 6)
Adell was very impressive with the bat in Summer Camp, but there were reports of him struggling a bit defensively in right field. Don’t look for that to be a long-term issue and expect him to force his way into the outfield rotation during his time in the Angels’ alternate camp. Los Angeles should be a better team with Adell in right eventually, with Brian Goodwin shifting to a fourth-outfielder role.

Astros: Forrest Whitley, RHP (No. 1/MLB No. 19)
Though his last two seasons have been marred by a suspension, minor injuries and command issues, Whitley still displays five different pitches that can grade as plus or better. The 2016 first-rounder from a Texas high school could be a major upgrade for a Houston rotation that looks shaky on the back end.

Mariners: Jarred Kelenic, OF (No. 1/MLB No. 11)
Yes, this might be a long shot, but it could be one worth playing. Kelenic was on fire during Summer Camp and certainly feels like he belongs. At the very least, the 2018 first-rounder has pushed up his ETA. But the Mariners only have two true outfielders on their big league roster right now and it’s not too difficult to see a scenario when Kelenic is raking in alternate camp and Seattle needs a third outfielder, right?

Rangers: Demarcus Evans, RHP (No. 22)
Teams may lean on their bullpens more than ever during this unique season, and Evans led all Minor League relievers in strikeout rate (16.6 per nine innings) in 2018 and opponents batting average (.119) last year. A 25th-round steal out of a Mississippi high school in 2015, he has a 93-96 mph fastball that plays up because of spin rates and extension, and he backs it up with a hammer curveball.

NATIONAL LEAGUE EAST

Braves: Bryse Wilson, RHP (No. 6)
There was a chance Wilson was going to break camp with the big league team as the Braves looked at piggyback-type systems for the back of their rotation. He’s been up and down a bit over the last two years, and it remains to be seen if he’s a starter or reliever long-term, but it’s probable the big league staff will need his help in some capacity in 2020.

Marlins: Monte Harrison, OF (No. 9)
The potential key to the package Miami received from the Brewers for Christian Yelich in January 2018, Harrison performed well in Spring Training (.987 OPS, six steals in 17 games) and Summer Camp. Perhaps the best all-around athlete in the Minors, he could win a starting job before too long and be the Marlins' most productive outfielder this year.

Mets: David Peterson, LHP (No. 10)
Taken 20th overall in the 2017 Draft out of Oregon, Peterson made a successful jump to Double-A last season and continued to pitch in the Arizona Fall League. The 6-foot-6 southpaw generates a healthy number of whiffs and has long been revered for his ground-ball tendencies, and as the Mets’ most advanced starting pitching prospect, he’s a candidate to join the rotation when the need arises.

Nationals: Luis García, SS/2B (No. 2/MLB No. 97)
García opened the 2019 season as the youngest player (18) at the Double-A level and struggled early before turning it on in the second half, batting .272 with 22 extra-base hits, including four home runs, over his final 65 contests. The Nationals have been aggressive with the teenager’s development after signing him for $1.3 million in July 2016, and it wouldn’t come as a surprise if the club were to call upon him to contribute in the Majors during this year’s shortened season.

Phillies: Spencer Howard, RHP (No. 2/MLB No. 34)
While it would be fun to also see top prospect Alec Bohm in the big leagues, there’s a better chance that Howard will be called upon in Philadelphia. The right-hander, who dazzled in the Arizona Fall League last year, was so dominant in Summer Camp, Bryce Harper basically demanded he be a part of the rotation this year.

NATIONAL LEAGUE CENTRAL

Brewers: Drew Rasmussen, RHP (No. 9)
The Brewers took Rasmussen in the sixth round of the 2018 Draft hoping that the hard-throwing right-hander would make a healthy recovery from his second Tommy John surgery. He did just that in ’19, flashing dominant stuff (96 K in 74 1/3 IP) while ascending from Class A to Double-A in his pro debut. He has the potential to serve as a lights-out reliever this season and is capable of pitching multiple innings.

Cardinals: Dylan Carlson, OF (No. 1/MLB No. 17)
The 2016 first-rounder broke out in his age-20 season, hitting .292/.372/.542 with 26 homers and 20 steals in 126 games across Double-A and Triple-A. The performance netted Carlson, a switch-hitter, Double-A Texas League Player of the Year honors, and he posted a 1.098 OPS with five homers in 18 games after advancing to Memphis. Carlson’s five-tool profile enables him to impact games in a variety of ways and it‘s only a matter of time until the Cardinals turn him loose in an everyday role.

Cubs: Adbert Alzolay, RHP (No. 6)
Tyler Chatwood and Alec Mills are far from sure things in a rotation on a team determined to return to the playoffs, and Alzolay could prove to be a better option than either. Signed for just $10,000 out of Venezuela in 2012, he has been slowed by lat, side and biceps injuries the last two years but possesses a mid-90s mph fastball with running action and a low-80s curveball with nice depth.

Pirates: Ke'Bryan Hayes, 3B (No. 2/MLB No. 41)
Had Hayes not tested positive for COVID-19 and missed Summer Camp, it’s possible he would have at least made decisions difficult for the Pirates’ new front office. He’s still the future at the hot corner for this organization and if he can get himself going in alternate camp, he could push Colin Moran into more a backup corner infield/DH type.

Reds: Tyler Stephenson, C (No. 3)
Yes, the Reds technically do have three catchers on their roster, but Kyle Farmer could end up seeing a lot of time at shortstop. And we all know how frequently catchers can get hurt. Stephenson had a strong 2019, capped off by a very good Arizona Fall League, and impressed during his time in Summer Camp.

NATIONAL LEAGUE WEST

D-backs: Daulton Varsho, C (No. 3/MLB No. 76)
The Wisconsin-Milwaukee product moved up to Double-A last season and had a breakout offensive campaign, slashing .301/.378/.520 with 18 homers, 25 doubles and 21 steals (all career-high totals) in 108 games. While he still has defensive gains to make behind the plate, he’s also the rare athletic catcher who could be moved to another position -- he held his own in center field in the Southern League playoffs -- to help get his bat in the lineup.

Dodgers: Gavin Lux, SS/2B (No. 1/MLB No. 2)
In an upset, Lux didn't make the Opening Day roster, but could be a major part of Los Angeles' World Series push. A first-round pick in 2016 as a Wisconsin high schooler, Lux combines plus hitting ability, power and speed and made history last October by becoming the youngest player (age 21) ever to hit a pinch-hit home run in the MLB postseason.

Giants: Joey Bart, C (No. 1/MLB No. 14)
With Buster Posey electing not to play this season, Bart's ETA sped up. The No. 2 overall pick in the 2018 Draft from Georgia Tech, he should provide power as well as fine work behind the plate, though San Francisco will try its best to avoid rushing him because he has played just 22 games above Class A Advanced.

Padres: MacKenzie Gore, LHP (No. 1/MLB No. 5)
The No. 3 overall pick in the 2017 Draft overcame the blister problems that plagued him in 2018 to earn MLB Pipeline Pitcher of the Year honors last year, after posting a 1.69 ERA, a 0.83 WHIP and 135 strikeouts over 101 innings between Class A Advanced Lake Elsinore and Double-A Amarillo. The Padres pushed many of their top pitching prospects up to the Majors last season, and that trend should continue with Gore, who should quickly establish himself as one of the game’s premier young hurlers despite the shortened 2020 season.

Rockies: Brendan Rodgers, 2B/SS (No. 1/MLB No. 29)
It seemed possible that Rodgers could land on the big league roster on Opening Day as the club’s second baseman, moving Ryan McMahon to first and Daniel Murphy to a DH role. But the Rockies have some second-base depth, so Rodgers will have to continue getting work in at the Rockies’ alternate camp. He reportedly put on a lot of good weight and was carrying himself with more confidence in Summer Camp. He’ll be back, and soon.