The Rookie-level Arizona Complex and Florida Complex leagues began play Saturday, a month earlier than they did a year ago. The changes mean that the circuits will be populated more by players making the jump from the Rookie-level Dominican Summer League the season before and less by guys coming out of the current year's Draft. The DSL will begin play next month, as usual.

While the ACL and FCL remain five levels removed from the Majors, they are stocked with intriguing prospects. Below we rank the 10 best complex leaguers, with their organization Top 30 rankings in parentheses. All eight of the position players are making their U.S. debuts.

1. Brock Porter, RHP, ACL Rangers (No. 3/MLB No. 79)
Signed for a fourth-round-record $3.7 million as the best high school pitcher in the 2022 Draft, Porter began this season in High-A but walked 13 in 8 1/3 innings before the Rangers sent him to the ACL to recalibrate. When he's right, he has a 94-97 mph fastball that reaches triple digits with run and carry, a solid mid-80s slider and a quality low-80s changeup that tumbles and fades.

2. Starlyn Caba, SS, FCL Phillies (No. 5)
One of the top players in the 2023 international signing class, Caba received $3 million in January of that year. He whetted the Phillies’ appetite by hitting .301 with a .423 OBP while playing elite-level defense at short in his DSL debut. He’s a switch-hitter who makes a ton of contact and has great instincts on the basepaths. There’s going to be some sneaky pop, and he already went deep over the first couple of FCL games.

3. Felnin Celesten, SS, ACL Mariners (No. 5)
This is the first real look anyone is getting at Celesten, who signed for $4.7 million as the No. 2 prospect on MLB Pipeline’s 2023 International Top 50, because he suffered a Grade 2 hamstring injury before the DSL season even began last summer. He’s a switch-hitter with tremendous ceiling and he’s already added 10-15 pounds of muscle to his frame. He has impressive instincts, range and arm that point to a long-term future at shortstop.

4. Henry Lalane, LHP, FCL Yankees (No. 8)
Born in the Bronx as the son of a former St. Francis and European professional basketball forward of the same name, Lalane moved to the Dominican Republic as a youth and signed for $350,000 in 2021. He stood out as the best pitching prospect in the FCL last year, displaying a lively mid-90s fastball and flashes of a plus slider and changeup. The Yankees sent him back there while he nurses a shoulder injury, and it's unclear when he'll make his 2024 debut.

5. Paulino Santana, OF, ACL Rangers (No. 13)
Ranked No. 2 on our 2024 International Top 50, Santana signed for $1,297,500 out of the Dominican Republic after earning comparisons to Julio Rodríguez for both his five-tool potential and his personality. He's advanced at the plate, projects to hit for power and average and can make an impact on the bases and in center field with his plus speed.

6. Walker Martin, SS, ACL Giants (No. 4)
Martin led U.S. high schoolers with 20 homers and 75 RBI in 29 games in 2023, and the Giants considered taking him in the first round before being delighted when he was still available in the second. As a bigger-bodied shortstop with left-handed power potential, he draws some comparisons to Corey Seager.

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7. Fernando Cruz, SS, ACL Cubs (No. 10)
A cousin of former Cubs All-Star Starlin Castro, Cruz signed out of the Dominican Republic in January for $4 million, the second-largest bonus in franchise history for an international amateur. He offers more power than most shortstops, along with plus speed and smooth actions that should keep him at the position.

8. Rayner Arias, OF, ACL Giants (No. 5)
Arias has an intriguing combination of hitting ability, power and discipline, and he broke into pro ball by hitting .414/.539/.793 in 16 DSL games last summer before fracturing his left wrist making a diving catch. The son of Pablo Arias, who reached Triple-A as a right-hander and now scouts for the Diamondbacks, Rayner signed out of the Dominican Republic in January 2023 for $2,697,500, the second-highest international bonus in franchise history.

9. Yoeilin Cespedes, SS, FCL Red Sox (No. 7)
One of the more advanced hitters in the 2023 international class, Cespedes turned pro for $1.4 million out of the Dominican Republic in January 2023. He won Red Sox Latin program player of the year honors following a .346/.392/.560 debut in the DSL, where he impressed with his advanced approach, bat-to-ball skills, exit velocities, baseball IQ and work ethic.

10. Jeremy Rodriguez, SS, FCL Mets (No. 12)
The Mets acquired Rodriguez from the D-backs for Tommy Pham at last year’s Trade Deadline and saw him go 19-for-45 (.422) with 11 walks and only four strikeouts over 13 games in the DSL after that. That contact rate, along with dependable defense at shortstop, helped make Rodriguez an early arrival stateside this spring and a Spring Breakout participant at 17 years old. As he continues to mature, the left-handed slugger could be an eventual plus hitter at a premium position.