It takes him 4 1/2 to five hours a day.
The 22-year-old equipment and clubhouse manager for the Jays' Dunedin farm team in the Florida State League collects the blue shoes after practice, loads them in a cart and then heads outside the locker-room. There he arranges the shoes neatly, grabs a chair, dons latex gloves, picks up what looks like an ice scraper — a brush with a blade at the end — and starts cleaning dirt off the soles with meticulous care.
Once that is done, there's some cosmetic work, wiping down the rest of the shoes to make them look as nice as possible.
When pre-season games start, he has a bat boy helping him so that cuts down on the time spent on the cleaning chore.
"This is my eighth spring training so we've got it down pretty pat," said Barker.
The pitchers are particularly keen to have a shoe devoid of mud, so they get maximum traction when they throw off the mound.
But Barker says all the players treat him like part of the team.
"All the players are very respectful about it," he said. "We do the best we can and we know if we don't do it good enough, we'll make sure to compensate the next day and do it better.
"Or if a player has a specific way they want it done, they'll come to us and tell us."
As you might expect, the rainy days are the worst because of the mud.
"We work a little extra on those," he said.
His secret? Scrubbing Bubbles bathroom cleaner for the exterior of the shoe. And when the clubhouse and reporters clear out and he has the place to himself, he turns up the tunes.
Barker's soundtrack is pure country, with Garth Brooks and Eric Church particular favourites.
Originally from Texas, Barker started as a bat boy with the Philadelphia Phillies in Clearwater. He did that for a year and then moved inside the clubhouse.
"As soon as I stepped inside, (I knew) it's what I wanted to do with my career," he said. "And seven years later, I'm still putting in time and still trying to make it."
After high school, he joined the Jays.
While the major league camp means plenty of work, Barker loves this time of the year.
"I wouldn't trade any of this for the world. Most people don't get to see the equipment side of it, the clubhouse side of it so it's always good to show other people what we do on a daily basis."
During the minor league season, Barker's duties include equipment, laundry, meals, travel and a more than a few other chores.
But he only has to clean the coaches' shoes. The minor-leaguers do their own.
Barker, who looks like one of the prospects he works with, enjoys seeing players he has known from the Dunedin team climb the ladder.
He knows players like Kyle Drabek and Travis d'Arnaud (now with the Mets) from the Philadelphia farm system. And this camp features Dunedin graduates like Anthony Gose, Ryan Goins, Jack Murphy, Sean Ochinko and Ryan Schimpf.
"That's the best part about my job down here, seeing those guys get to a major league spring training or reach their dream of making to the big leagues," said Barker. "That's more rewarding than anything for me."
Schimpf recalls Barker from his Dunedin playing days.
"He's really first-class ... He's always there to help you out, whatever you may need," he said.
Like the players, Barker wants to move up in the baseball world. And is willing to pull up roots as needed.
"As long as there's cleats to clean and laundry to do, I'll go anywhere."