Ackley, the No. 2 overall selection in the First-Year Player Draft last June, was a three-time All-American at the University of North Carolina -- the first two years as a center fielder and the third year as a first baseman.
He holds the record for most career hits in the College World Series and batted at least .400 in each of his seasons with the Tar Heels.
The Mariners initially planned to send Ackley back to the outfield, where he played during the Arizona Fall League. But after further review, the organization decided to give the slightly-built left-handed hitter some work at second base.
"This could be an experiment that lasts two weeks or a month," general manger Jack Zduriencik said on Dec. 20, "but to me, the sensible thing to do is have players play multiple positions. We thought this would be a worthwhile experiment and we'll see where it takes us. We're not etching this in stone or saying this is a career move."
But you might want to grab a hammer and chisel.
"We are really happy with his progress" Grifol said. "It's going well."
With Ichiro Suzuki in right field for at least three more seasons, and Franklin Gutierrez in center field for at least the next four, the chances of Ackley reaching the Major Leagues quickly as an outfielder are less than if he played another position.
Ackley has been working out at second base since Jan. 4 at the Peoria Sports Complex, fielding ground balls and learning the position from Darren Garner, the Minor League infield coordinator, and Andy Stankiewicz, the Minor League field coordinator.
"First of all, he has terrific balance," said Grifol, an infielder during his playing days. "He also has a low center of gravity, is extremely flexible, has soft hands and knows what a ground ball looks like, having played both sides of the infield, shortstop in high school and first base in college.
"He has the tools needed to play second base. All we have to do with him is refine those tools, which are raw right now, and turn it into one package -- a second baseman."
Ackley currently is taking a four-day break from the workouts to attend the Major League Career Development in Dallas, along with Ezequiel Carrera, Nick Hill and Danny Cortes.
Practice resumes on Monday and continues through a mini-camp, which begins on Feb. 1.
A big step in his position switch comes in March, when Ackley begins playing games at second base.
"We can go out there and work with him and he could look great," Grifol said, "but once the game begins, everything speeds up, including the mind. When that happens, his game instincts need to kick in. How he handles that will be the true challenge.
"He 's looking great right now, but we haven't put him in any games. We're anxious to see what he is going to do in a game, but everything we have seen so far tells us this thing can work out. He's extremely confident, receptive and has a great attitude.
"I don't like to jump the gun and say it's going to happen, but in Dustin's mind, he thinks it will happen and is determined to make it happen."