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Two of baseball's most promising rookie outfielders will share a field beginning tonight, as Corbin Carroll and the Arizona Diamondbacks visit St. Louis for three games against Jordan Walker and the Cardinals. Carroll and Walker entered the spring ranked by CBS Sports as the Nos. 2 and 6 prospects, making them top contenders for the National League Rookie of the Year Award (they are the top two favorites for the award entering Monday, per Caesars Sportsbook).

The season may be young, but with such a fun matchup on deck we figured this would be a good time to check in on how Carroll and Walker have performed through the first few weeks of their rookie seasons, and whether or not we're encouraged or discouraged by their play to date. 

Corbin Carroll, OF, Diamondbacks

What we wrote in the spring: "Carroll was limited by injuries and the COVID-19 pandemic to 142 minor-league games ahead of his debut in Arizona last August. The lack of repetitions didn't prevent him from batting .260/.330/.500 (133 OPS+) with four home runs and two steals in 32 games. Carroll continued to exhibit swing-and-miss tendencies within the zone, ranking in the 27th percentile in that respect. That flaw won't sink him (Paul Goldschmidt and Gunnar Henderson were just two recognizable names around him on the leaderboard), but it may result in a higher strikeout rate than he was expected to post in the past. Still, Carroll is a well-rounded center fielder with top-of-the-scale speed who ought to provide oodles of secondary value."

How he's performed so far: Carroll entered Monday batting .288/.300/.542 with four home runs and six stolen bases (on six attempts). He has not taken a free pass in his first 60 plate appearances, a surprising development from someone whose career minor-league walk rate exceeded 15%. For whatever reason, be it his placement in the order (he's batted fifth most often) or internalized pressure to justify his $111 million extension, he's instead readily expanded his zone. His chase rate ranked in the 13th percentile coming into Sunday.

Carroll, to his credit, has hit the ball hard and at optimized angles at better-than-average rates. He even connected for a 432-foot home run against Clayton Kershaw, confirming he has more juice than his stature indicates. Speaking of doing damage against the Dodgers, five of his six steals have come versus Los Angeles, including three off Noah Syndergaard. (Poor Will Smith didn't even attempt a throw on three of those five Carroll steals.)

Carroll has leveraged his speed in the outfield, too, where he's already seen action at all three outfield spots (albeit with most of it coming in left). He could credibly play center field on an everyday basis, but the Diamondbacks are committed to giving Alek Thomas another extended trial in center. The early returns on Thomas have not been encouraging, so that dynamic could change over the coming weeks if the D-Backs grow uninspired. 

Encouraged or discouraged? Encouraged. Carroll isn't going to go without a walk all season. The rest of his game has been as good as advertised, and it shouldn't surprise anyone if his best play is ahead of him.

Jordan Walker, OF, Cardinals

What we wrote in the spring: "Walker has immense strength, resulting in the kind of raw power that could make him a prototypical middle-of-the-order slugger. In order to fully access that pop, scouts expect that he'll need to continue to learn how to lift the ball more frequently -- last season, more than 45 percent of his batted balls were grounders. (A point in his favor is that most evaluators believe it's easier to train launch angle than exit velocity.) There was always a chance Walker would outgrow the hot corner, and the Cardinals have already taken to cross-training him in the outfield. Whatever position Walker ends up playing, his bat will be the main draw."

How he's performed so far: Walker received national attention for beginning his career with a 12-game hitting streak that tied a century-old record for players aged 20 or younger. He entered Monday batting .267/.302/.400 with two home runs and a stolen base. Walker's introduction to the majors, like Carroll's, has not featured many walks. He's drawn one in his first 63 trips to the plate, all the while recording 17 strikeouts. He's been hyper-aggressive to date, swinging at more than 72% of the pitches he's seen in the zone, as well as more than 37% of those located outside of the strike zone.

Walker's bat is (and was expected to be) a work-in-progress as he learns to lift the ball more frequently. Sure enough, he's shown top-end raw strength, delivering a maximum exit velocity (114 mph) that puts him in the 97th percentile in that measure (around the likes of Vladimir Guerrero Jr. and Ronald Acuña Jr.). At the same time, he's sporting a well-below-average .133 ISO because of a 53.5% ground-ball percentage. What's more is that his two hardest-hit balls this season have had negative launch angles. 

Defensively, Walker has played only right field this season after being drafted and (mostly) developed as a third baseman. He's more athletic than his size and strength indicate, but at times he's looked like someone with about 50 games of professional experience out there. Ultimately, whatever Walker gives (or takes) on defense won't matter that much -- not if everything clicks offensively and he's annually threatening for the league lead in home runs.

Encouraged or discouraged? Encouraged. Walker will need to tighten his approach as the year burns on, and we suspect he's going to have stretches where he's hitting nothing but loud ground outs. Still, it's promising that he's holding his own so far as a 20-year-old.