"I know I made a mistake," Zambrano told MLB.com on Tuesday. "I'm a person and a human, and I know when I make a mistake. I have to come to the team and apologize.
"I'm not going to [apologize] because [the Cubs] said I have to do it," he said. "I'm going to do it from my heart. I want to be clear and at peace with my teammates."
Zambrano spoke to MLB.com before traveling to Albuquerque with the Triple-A Iowa team. Currently on the restricted list for Chicago, he was expected to pitch Tuesday or Wednesday, and then be activated Friday when the Cubs begin a three-game series in Denver against the Rockies. He has made two appearances with the Iowa Cubs so far.
He did an interview Monday with ESPN, and said he was motivated to do that in an attempt to clear up some misunderstandings. The Iowa Cubs had announced that Zambrano would talk last week when he reported to the team, but he didn't. He also did not talk to the media after his outing in Des Moines and said Tuesday that he was told not to speak to reporters by the Cubs front office.
"I saw a little bit of [the ESPN interview]," Cubs manager Lou Piniella said Monday of Zambrano's comments. "I'm sure he's contrite, and I'm sure he's looking forward to coming back, but the important thing remains that he talk to his teammates."
Zambrano said Tuesday that he wanted to apologize to his teammates immediately after the incident on June 25 at U.S. Cellular Field, but he was told by the Cubs to stay away. However, all sides agreed at that time, including Zambrano and his representatives, that he needed to undergo treatment before meeting with the players.
"I don't like to lie," Zambrano said. "I wanted to do this way before this time. I wanted to come to the clubhouse and apologize and talk to my teammates."
Zambrano spoke to ESPN because he was frustrated that he could not speak to the players. He said he's eager to make amends.
The right-hander said he was trying to fire up the Cubs after falling behind 4-0 in the first inning against the White Sox at U.S. Cellular Field. Three of the White Sox's runs that inning came on Carlos Quentin's three-run homer off an 0-2 pitch from Zambrano.
When the pitcher came off the field, he threw a tantrum in the dugout. Cubs first baseman Derrek Lee told Zambrano to shut up, the pitcher said.
"I apologize from the bottom of my heart," Zambrano told ESPN. "The last person I would be mad at is D-Lee. He's a Gold Glover. I was just mad at myself."
Zambrano said he sent a text message to Lee two days after the incident and they talked. On Tuesday, he confirmed that the two have spoken.
The pitcher was suspended for three days without pay after the incident and then placed on the restricted list to undergo treatment for anger issues.
"I said that time heals wounds, and that's exactly what has happened, but I'm sure his teammates want to hear what he has to say, and we'll go from there," Piniella said Monday. "With time, you tend to forgive and forget."
Zambrano said he does not want to leave the Cubs, saying he "came on a mission, and I want that ring."
He also said the therapy sessions have helped.
"A lot of people have told me I need to change if I want to be successful," Zambrano told ESPN. "Thank God the Cubs have sent me to the doctor for anger management. I've had three sessions already ... doing exercises. I have to write down every time I get mad."
Zambrano has yet to pitch in back-to-back games, but Piniella said he didn't think that was necessary.
"He's probably champing at the bit to get back into the fray," Piniella said, "and hopefully he'll come back and help us win some baseball games."
Carrie Muskat is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.