2:56pm: The Cubs have placed Zambrano on the disqualified list, reports Sullivan (all Twitter links). Zambrano can not be with the team for 30 days and will not be paid during that time. MLB and the players' union will use the 30 days to discuss the next step, according to Gordon Wittenmyer of The Chicago Sun-Times (on Twitter).

Ken Rosenthal of FOX Sports reports (on Twitter) that the union will file a grievance on Zambrano's behalf, challenging the decision. Praver told Hendry that his client "is not in the retirement mode," and the GM also said he "[feels] badly about action towards Braves." He said saying that throwing at Chipper was "inappropriate."

12:52pm: Hendry and Praver have been discussing the situation and are trying to figure out "what Zambrano was actually thinking," according to Sullivan. If things are not resolved by this afternoon, Sullivan says the Cubs are likely to place the right-hander on the restricted list indefinitely. He has not filed retirement papers.

Zambrano still got paid during last year's stint on the restricted list, but the move will free up a roster spot for the Cubs.

8:34am: Carlos Zambrano gave up five home runs to the Braves in 4 1/3 innings last night, then was ejected after throwing two consecutive inside pitches to Chipper Jones. After the ejection, Zambrano cleared out his locker and told the team trainer that he was retiring, according to Paul Sullivan of The Chicago Tribune (Twitter links).

"We will respect his wishes and honor them and move forward," said GM Jim Hendry, though manager Mike Quade was understandably angry with his right-hander. "I'm really disappointed. His locker is empty. I don't know where he's at. He walked out on 24 guys that are battling their (butts) off for him. I don't know where he's gone or what he's doing. I heard he has retired, or talking about retiring … I can't have a guy walking out on 24 guys, that's for damn sure."

There are a number of reasons to be skeptical about Zambrano's retirement talk. For one, he's always been a behavioral wildcard, but more importantly, there is over $22MM left on his contract, which he'd forfeit by retiring. Zambrano is represented by Barry Praver of Praver Shapiro Sports Management, who will surely try to talk his client out of calling it quits.

The Cubs suspended Zambrano indefinitely following another tirade last June, keeping him on the shelf for a little more than a month. The team also suspended Milton Bradley for "conduct detrimental to the team" in September 2009, forcing him to sit out the rest of the year before trading him in the offseason. It seems unlikely that Zambrano will follow through on his retirement talk, but the Cubs could be so tired of his act that they'll trade him this winter no matter what the cost, similar to what they did with Bradley.

Zambrano, 30, owns a 4.82 ERA with career lows in strikeout (6.2 K/9) and ground ball (42.4%) rate this season. He is owed just over $4MM for the remainder of 2011 plus $18MM in 2012. A $19.25MM vesting option for 2014 based on Cy Young Award finishes is unlikely to kick in. Zambrano also has a full no-trade clause in his contract, but that didn't stop the Cubs from trying to unload him before the trade deadline.