Pratto, 18, is off to somewhat of a slow start in the Arizona Rookie League, hitting .218 with two home runs and 18 RBIs in 22 games.
Center fielder Khalil Lee, a third-round pick in the 2016 Draft, has shown exceptional power and is No. 2 on the list after being No. 14 preseason. Lee, 19, has 13 home runs and a .433 slugging percentage at Class A Lexington.
Hunter Dozier, an outfielder/third baseman, dropped from No. 2 to No. 3. He has missed almost the entire season because of injuries.
Outfielder Seuly Matias, an undrafted free agent signed out of the Dominican Republic who is 18 years old but already a solid 6-foot-3 and 200 pounds, jumped to No. 4 on the list after being No. 10 preseason. In his first season at Rookie-level Burlington, Matias has an .858 OPS.
Left-hander Foster Griffin, the Royals' first-round pick in 2014, jumped from No. 22 on the list to No. 6. Griffin was promoted to Double-A Northwest Arkansas this summer and also pitched for Team USA in the Sirius XM All-Star Futures Game earlier this month.
Right-hander A.J. Puckett, a second-round pick in 2016, went from No. 11 to No. 13 on the list. Puckett has a 3.87 ERA this season at Class A Advanced Wilmington.
The ranking of baseball's top prospects is done by MLBPipeline.com Draft and prospect experts Jonathan Mayo, Jim Callis and Mike Rosenbaum, who compile input from industry sources, including scouts and scouting directors. It is based on analysis of players' skill sets, upsides, proximity to the Majors and potential immediate impact to their teams. Only players with rookie status are eligible for the list. Players who were at least 23 years old when they signed and played in leagues deemed to be professional (Japan, Korea, Taiwan, Cuba) are not eligible.