Chicago Cubs catcher Michael Barrett, right, and pitcher Carlos Zambrano get into a heated exchange after the last out of the top of the fifth inning of Friday's game against Atlanta at Wrigley Field. Pitching coach Larry Rothschild, left, and other teammates try to get between the two players.

CHICAGO — It has come to this with the Cubs: Unable to beat other teams, they have started beating on each other. Unable to settle things in private meetings, they have taken to public airwaves.

Frustration, then futility and finally fisticuffs.

In the midst of losing their fifth straight game and 11th in the last 15 — 8-5 to Atlanta on Friday at Wrigley Field — batterymates Carlos Zambrano and Michael Barrett tussled in the dugout and then apparently had an all-out set-to in the clubhouse.

It left Barrett in the hospital with a badly bruised lip, Zambrano alone to celebrate his 26th birthday and teammates wondering what happened.

While manager Lou Piniella pledged there would be disciplinary action after he meets with both players before Saturday's game, several teammates said they were "embarrassed" by this season spiraling into insignificance.

"We're not putting everything together now and that (fight) happens," said Alfonso Soriano, the team's highest-paid player. "So I'm embarrassed for everybody here because we're supposed to be like a family and that's not supposed to happen."

Of course the team wasn't supposed to be 22-30 at this point of the season, one marred by baserunning blunders, bad fielding, untimely hitting and inept relief pitching.

The disappointing play had been irritating the Cubs for days and it finally boiled over Friday after an unsightly top of the fifth inning in which Zambrano allowed five runs on five hits and Barrett was charged with a passed ball and a throwing error on the same play.

Emotions had been building the entire game, as Zambrano became frustrated by sloppy play. Shortstop Ryan Theriot missed a popup on the first play of the game that led to a run and right fielder Matt Murton's error on a dropped fly accounted for another run in the fourth inning.

Then came the fifth when Zambrano walked the leadoff man and Barrett committed his error. After Barrett's miscues, Zambrano allowed a single to .189-hitting Pete Orr and a double to pitcher Kyle Davies, a .067 hitter.

When the inning finally ended, Zambrano approached Barrett in the dugout and pointed to his head while yelling. Barrett motioned toward the outfield or scoreboard and said something back. Zambrano then took a swipe at Barrett's head and the two exchanged brief blows before being separated.