Barrett's suspension began with Monday night's interleague game against the Indians. He will be eligible to play again June 30 against the White Sox.
"I'm disappointed, but there's nothing we can do about it," Cubs manager Dusty Baker said.
The Cubs are not allowed to add a player to the roster during the suspension. Henry Blanco will see the majority of playing time behind the plate. Phil Nevin, who subbed at catcher for one inning on Sunday, will be the backup.
Barrett and Pierzynski were involved in a collision at the plate in a May 20 game at U.S. Cellular Field. Pierzynski scored on the play, knocking Barrett to the ground. Pierzynski then slapped home plate and bumped into Barrett after the play. Barrett responded by punching Pierzynski in the face, triggering a bench-clearing brawl.
Barrett appealed the suspension and a hearing was held with John McHale Jr., executive vice president for administration for Major League Baseball, at Wrigley Field on Friday.
"We brought in some precedence of similar fights in the past that ended up being less that my suspension," Barrett said. "Obviously, it's 10 games. I've got to serve it and put it behind me. I knew there would be consequences for my actions."
Barrett, batting .308 with eight homers and 30 RBI this season, had missed the previous three games with a sore back but said he was scheduled to play Monday night. He can participate in the Cubs' pregame workouts but has to leave the ballpark when the game begins.
"It's going to be tough to stay sharp in baseball terms," he said.