The high-energy former Cubs pitcher can still show intensity, but under new manager and friend Ozzie Guillen, Zambrano seems to have learned how to harness his inner demons for the benefit of himself and his teammates.
It comes too late for those in the Cubs' clubhouse, who witnessed the occasional counter-productive meltdown. That's not to say the right-hander wasn't productive during his 11 seasons with the Cubs, going 125-81 with a 3.60 ERA.
"I saw this man was like a bull when he goes to the ring," Guillen said Sunday in Miami. "He was just attacking people all over the place. I see it that way. He doesn't know who he's going to kill. Now he's more calm and I think maybe because he has matured a little more. Maybe (it's) because people aren't going to put up with his (nonsense) anymore."
Guillen didn't say "nonsense," of course. He dropped an unflattering expletive, showing that he knew exactly what he was getting into when the Marlins traded for him this winter.
What the Marlins have received in return is mixed. In 17 starts (before Monday) Zambrano was 4-7, hardly impressive but run support gets some of the blame. He has a 4.20 ERA, not exactly eye-popping, but there are some nice internal numbers.
Zambrano has given up 86 hits in 100 2/3 innings and of the five Marlins pitchers who have already reached 100 innings this season, he is the only one to give up fewer than 100 hits. His eight home runs allowed are second best on the staff to Josh Johnson's six.
Guillen and Zambrano both hail from Venezuela, and Guillen was often the person who consulted the pitcher after his infamous blowups. But Guillen balks at taking the credit for what seems to be a more focused Zambrano.
"Whatever the reason is, maybe it's because his religion helped him, his family," Guillen said. "A lot of people take credit that don't need (to take) credit. I have nothing to do with this. I told him exactly what I want and he's been doing that. I'm not going to take credit: ‘Oh, he's better because I'm tough.' No, he's better because he wants to be better."
Amazing as it sounds, Guillen seems to think that Zambrano might be too passive now.
"I think sometimes Carlos tried to take something off to throw a strike and that's not the approach to take," Guillen said. "When you take something off to throw a strike and that thing is going to be over the plate with nothing on it then you're going to get whacked. I would rather have him to throw (hard) no matter how it is. It takes a little while for that process but it's been a lot better."
Buy anybody disappointed that Zambrano couldn't take this new approach while he was with the Cubs, Guillen and the new surroundings were probably the biggest reason it is happening now.
"I believe in him because I know what he can do," Guillen said. "I'm not going to say do this or that and I know he can't do it. I told the Marlins to not worry about him off the field because I think I know him pretty well. And he needed change. It was good for everyone. I'm not just going to talk about this side I'm going to talk about the other side too. It's better for everyone."