The Cubs also claimed infielder Cody Ransom off waivers from the San Diego Padres, added pitchers Kevin Gregg and Kameron Loe to the 25-man roster and designated infielder Brent Lillibridge and left-hander Hisanori Takahashi for assignment. They also optioned reliever Rafael Dolis to Triple-A Iowa.
"Takahashi was here to pitch long and that's not really where we were weak," Cubs general manager Jed Hoyer said. "Gregg has more stuff and can pitch later in the game. Loe gives us a sinkerball guy and a style of pitcher we don't have in the bullpen right now for (manager) Dale (Sveum). We don't really have one down there to get us a ground ball to get us out of a jam and we think Loe can do that."
Barney will make his season debut Tuesday against the Rangers after missing the first 12 games because of a cut on his knee that required five stitches during their final spring training game. The Gold Glove-winning second baseman played at Triple-A Iowa over the weekend on a rehab assignment.
"I'm going to wear a pad thing in case I come down on it hard, just to protect the injury," Barney said of his knee. "Nothing will split it open but just to be safe, I think I'm going to wear it for a few more days."
Ransom, a .215 career hitter, has played with seven teams over 10 seasons. He played in five games with the Padres this season, going hitless in 11 at-bats.
Gregg was signed over the weekend after the Cubs placed closer Kyuji Fujikawa on the disabled list with a forearm strain. The former Cub was a late cut by the Los Angeles Dodgers in spring training. The 10-year veteran has 144 career saves, including 23 with the Cubs in 2009, but Sveum said he will continue to mix and match pitchers to close games.
"It's what I'e done in the past," Gregg said. "Talking to these guys, it was a matter of bringing in some experience at the back end. I'll be able to help with that."
Loe, 31, has played with three teams over eight seasons, spending five with the Rangers from 2004-08. He was placed on waivers by the Seattle Mariners after posting a 10.80 ERA over four appearances, and he was claimed by the Cubs on Sunday.
Lillibridge has one hit in 24 at-bats (.042), mostly filling in for Barney at second base and sharing time with Luis Valbuena at third base.
Dolis pitched 1/3 of an inning against the San Francisco Giants on Sunday in his only appearance this season.
Takahashi, signed in the offseason by the Cubs, has a 6.00 ERA in three appearances.