The Cubs filed a report on the incident, and general manager Jim Hendry said he hopes to get a response "in the next day or so" after the league and players union look into it.
Zambrano, who has a history of outbursts, unleashed a tirade against his teammates and had to be separated from Derrek Lee in the dugout after allowing four runs in the first inning of a 6-0 loss to the White Sox. He was sent home by manager Lou Piniella, suspended indefinitely by the team and won't have a spot in the rotation when he comes back.
Hendry, speaking before Sunday's game, said he's been in contact with Zambrano's agent Barry Praver but not the pitcher. Nor has manager Lou Piniella.
"I think until something gets rectified, the less conversation the better," Piniella said.
The Cubs entered Sunday's game against the White Sox at 32-42, and Zambrano hasn't pitched to the level that led to his $91.5 million, five-year contract extension three years ago. He's 3-6 with a 5.66 ERA, and the outburst wiped out most if not all the good will he earned by accepting his five-week assignment in the bullpen.
When he does return, Hendry said Zambrano will have some fences to mend with his teammates.
"The last few years, when he hasn't pitched as well, there've been some other instances that I don't think he would have been referred to as the ideal teammate," he said. "That's for him to rectify with his own teammates and how they handle him. That wasn't the first instance where the best teammate wasn't exhibited."
Will the Cubs look to deal Zambrano, who has a full no-trade clause?
"I never talk about ever potentially trading any of our players," Hendry said.
Would the Cubs be better off keeping Zambrano in the rotation and showcasing him?
"First of all, I never get into talking about potentially trading any of our players," Hendry said. "Secondly, the word showcase doesn't exist to me. People have plenty of time to scout players, present and past. That's just something I would never get into."
Hendry also would not say if Zambrano has been to anger management counseling.
Praver did not respond to messages seeking comment.
In the latest episode, Zambrano apparently was upset because some teammates didn't try to make diving stops on some balls that were hit hard.
That includes a leadoff double by Juan Pierre down the right field line past Lee and another with one out by Alex Rios down the left field line past third baseman Aramis Ramirez to drive in the first run. And when the inning was over, Zambrano delivered his latest outburst.
Zambrano didn't help his standing in the organization by going to dinner Friday with White Sox manager Ozzie Guillen, who advised his friend and fellow Venezuelan to "face it like a man."
Hendry, who was not at the ballpark on Saturday, said, "I would think in those types of circumstances that even if you had it planned before that better judgment would have kept you home that night. Ozzie and I are good friends, too. It's certainly not his fault; he just kept his end of a prearranged dinner. But if you go through what you did that day and go through what you did with your teammates that day, you might be better served staying home."
Piniella again said he wasn't happy about that and pointed out that he stayed home after Friday's game rather than go to dinner with his wife and daughter, who he had not seen since February.
"My wife and daughter wanted me to go eat dinner with them," he said. "I was sick with what happened, and I was very tired."