MESA, Ariz. -- It's not that Carlos Zambrano isn't earnest. Even in his worst moments, he wanted you to believe him. And Cubs fans, God love 'em, needed to believe him back.
But this spring just seems different.
For starters, there's about 15 pounds less of the player whose designation of Cubs' ace was on the wane in 2008 and took a hiatus in 2009. But more than that is a sense of accountability that was not always there in the past.
"Anyone can change their life, even if they're 40 or 50 [years old]," Zambrano said Tuesday in Mesa. "Put something in your mind and concentrate and don't do it anymore, you won't do it."
Of course, under blue enough skies and a warm enough sun, anything seems possible, particularly after a longer and colder winter than Zambrano has experienced in a very long time.
It was Zambrano's first Cubs offseason in which he stayed in Chicago full time and did not travel to his native Venezuela, a period of time in which he shoveled snow, stayed away from bad habits such as fried foods and sweets, and suddenly noticed that his three girls -- ages 9, 6 and 5 -- were growing up fast.
"My daughters are big now, they understand life," he said, "and that's another reason I have to control myself, don't let my daughters see any stupid things on the field. So that's why I have to change."
But it wasn't just the temper, which led to another confrontation with an umpire and suspension last season. Let's face it -- that likely will never change completely. More than that was a new sense of discipline that led him to drop the weight. That, and the realization that his days of rearing back and blowing a 95 mph fastball past hitters at will are largely behind him.
"I'm not an old man," he said, "But 28 is not the same as 20. It's harder now."
This spring, Zambrano has, if not abandoned, then moved away from his cut fastball and is working more on his slider. And aside from his giving up a grand slam in his second outing of the spring, there is ample reason to be optimistic.
On Monday, he allowed five hits and one earned run in four innings.
"He needs to stay ahead of the hitters; I think that's important," said Cubs manager Lou Piniella of his Opening Day starter. "But four innings and one run? We'll take that every time."
Cubs pitching coach Larry Rothschild, who along with Piniella urged Zambrano to lose the weight, believes it was largely responsible for his problems last season.
"I think it was a combination of some time on the DL," Rothschild said of Zambrano's two stints for a torn hamstring and back spasms. "His peripheral numbers weren't that much different than the year before, but he wasn't able to go out there as much and really pitch deep into games to get the wins.
"[Losing weight] can help clean up his delivery a little bit, too, where he's not fighting to get on top of the ball quite as much. But if he pitches well, it worked. If it doesn't, it didn't."
If it doesn't, Zambrano vows not to get in his own way.
"I don't even want to call [last season] frustration," he said. "It's more like taking everything to heart. I'm just trying to do everything right, and certain times, I try to be too perfect. I know we make mistakes, and I have to understand that a mistake is part of a game and you just have to leave those mistakes and be in control of what pitch you have to throw next."
Piniella said Zambrano was embarrassed last season.
"He's not a 9-7 pitcher," he said. "He shouldn't be a 9-7 pitcher we expect good things from him this season. There's no reason why Carlos can't get into the upper echelon of National League pitchers winwise this year."
It's certainly not as if the three-time All-Star hasn't done it before.
"This isn't like a project or anything," Rothschild reminds us. "It's just trying to get him back to pitching the way he can."
Zambrano's teammates feel the same way.
"I just want to see Carlos go back to a couple years ago and win games like he does," Derrek Lee said. "I've seen him win games when he looks big and win games when he looks skinny. I think the good thing about Carlos is he's focused and he's looking to bounce back from last year."
For his part, Zambrano sounds, if not reborn, at least re-energized.
"Every day I come to pitch, it means something," he said. "I come with an expectation to work and do my job for the Cubs and for myself, of course."
As Rothschild said, if he pitches well, it worked.
Melissa Isaacson is a columnist for ESPNChicago.com