"I'm not happy, happy about this decision," Zambrano said. "But I feel good about helping my team and to do everything to help solve whatever the problem is."
The problem, of course, was finding a reliable option in front of closer Carlos Marmol. Zambrano allowed a run on two hits in 1 1/3 innings in his relief debut on Saturday in Milwaukee. He's was available to work on Monday against the Nats.
"The Cubs pay me to pitch -- starting, relieving, closing, whatever they want me to do here."
Zambrano was struggling the most of any Cubs starter when the move was made. But, he insists that's not the reason he's in the bullpen.
"It's not the fact I was pitching bad," Zambrano said. "It was the fact we need somebody in the eighth inning."
Zambrano was happy overall with his relief debut, but admitted there's a physical adjustment period that takes place when making this sort of transition.
"I don't think my arm was ready," Zambrano said. "I have to concentrate and prepare more, to be a reliever. I've been a starting pitcher for six, seven years. This is a new role for me, and I have to get used to this role."
Making a salary of $17.85 million this season, Zambrano is the highest-paid setup man in baseball. But that's something that didn't factor in the decision.
"That's not what it's all about," Cubs GM Jim Hendry said. "If you're locked into salary, it's called 'win as many games with the quality of payroll that you have.' You can't worry about anybody's individual salary. That's why you make deals at deadlines; that's why you keep tinkering with things; that's why you always need guys coming up from the system.
"Nobody ever breaks camp with 25 in the same role and just run the table, win 100 and go through the playoffs. That's foolish thinking."
During Spring Training, Zambrano preached about a more mature attitude on and off the mound. So when asked by a reporter how he would've received the move a few years ago, he just smiled.
"What do you think?" he said in response to the reporter.
"A different Carlos wouldn't be smiling right now," he said. I would be [very mad] or disagree with the manager. I'm happy with the way things are right now."
Kerry Walls is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.