Ackley was assigned to the Double-A West Tennessee club, along with right-handed pitchers Ricky Orta, Danny Cortes and Anthony Varvara, and left-hander Edward Paredes. Outfielder Ezequiel Carrera was optioned to Triple-A Tacoma.
Ackley stood out during his monthlong stay in camp.
"He's doing really well, and we're extremely happy with his progress," Minor League director Pedro Grifol said. "We will continue to move forward to make him the best second baseman he can be."
Ackley, the second overall selection in last June's First-Year Player Draft, played center field the first two years at the University of North Carolina and first base during his junior year, earning All-America honors each year.
While Ackley was playing in the outfield during the Arizona Fall League, the Mariners decided to "experiment" and move him to the infield.
He has spent the past three months learning the new position.
"He is going to go out and play in games, and that's the most important thing," Zduriencik said. "You have to realize that every single time something happened to him in the field, it was the first time it happened at that position.
"It was the first time for a rundown, first time turning a double play, first time going after a popup in the outfield. That being said, he impressed with his athletic ability and day-to-day improvement."
Ackley played in 10 Cactus League games, going 3-for-19 with one triple and three RBIs. He walked twice and struck out just two times, a testament to his ability to put the ball in play.
"He's not going to get overwhelmed or overmatched anywhere," Grifol said. "He has a good knowledge of the strike zone, has a great swing and great hand-eye coordination. He's a good hitter, that's the reason we [drafted] him."
Tuesday was an off-day for the Mariners, and Ackley will join the Tacoma club on Wednesday. Later in camp, he probably will join West Tennessee and is tentatively scheduled to start the regular season with the Diamond Jaxx.
Grifol said he is not surprised Ackley has made so much progress so quickly, and he credits Minor League infield coach Darrin Garner for the success.
"First of all, Dustin's makeup is off the chart, and he works in a way he wants to be the best," Grifol said. "He took something like 10 or 12 days off after the Fall League and came back to Arizona to work out.
"The work they did prior to Major League camp was invaluable, but there's still a lot of work to be done. This, by no means, is the finished product."
Tuesday's cuts leave the Mariners with 45 players in camp, including 13 non-roster invitees. The team resumes the Cactus League schedule on Wednesday night against the Rangers at Peoria Stadium.