Infielder Alberto Gonzalez, who was with the club for their season-opening series in Pittsburgh in case it decided to place Barney on the DL, was added to the roster. Pitcher Robert Whitenack was designated for assignment to make room on the 40-man roster.
Barney, whose DL stint is retroactive to Sunday, hurt his left knee chasing down a popup in the Cubs' final exhibition game of spring training on Saturday in Houston.
"I thought by sliding I was protecting myself," Barney said Monday. "There's a concrete corner and slab on the bottom, ran right into that. When I pulled my pant leg up I was pretty freaked out."
Barney saw a deep gash where his left knee bends. He said if the cut, which required five stitches, was a little higher or lower it probably would not have been as serious.
"It's tough," he said. "You spend your whole offseason thinking about today. We had a good spring as a club. It's unfortunate."
Brent Lillibridge will start in his place and bat eighth against the Pirates.
Barney joins pitcher Matt Garza (left lat strain) and third baseman Ian Stewart (left quad strain) on the disabled list. Pitcher Scott Baker is on the 60-day DL as he recovers from Tommy John surgery.