The friends - and Venezuelan countrymen - felt working together would help accomplish both.
Guillen will give the ball to Zambrano for his Marlins debut Sunday when the volatile right-hander faces a familiar foe in the Cincinnati Reds at Great American Ball Park.
Zambrano spent 11 seasons with the Chicago Cubs, winning 125 games - more than double the total of the club's next pitcher on the list in that span.
He struggled to live up to the expectations of a No. 1 starter over the past three seasons, though, going 29-20 as the Cubs went from playoff contenders to a losing ballclub. The decline culminated in Zambrano posting a career-high 4.82 ERA last year.
At one point last summer, the Cubs even placed Zambrano on the 30-day disqualified list after he abruptly announced his retirement - an episode that only expedited his exit from the Windy City.
Guillen was willing to welcome his friend, whom the Marlins (1-2) acquired for fellow right-hander Chris Volstad.
"I expect him to have a good season," Guillen told the team's official website. "I always say, 'Whatever happened in the past, stays in the past.' This is a new year. He can open a new book. He's very happy here, and hopefully, it'll work for him."
Zambrano is enthusiastic to work for Guillen.
"Ozzie is one of the smartest guys I've ever met, and he's a good manager," Zambrano said. "He gives you confidence. If you play right for him, he has your back. He'll be there for you. I just want to enjoy this game and start from there."
Sprint training was rocky for Zambrano, who went 0-3 with a 6.23 ERA while walking 21 in 21 2-3 innings over six starts.
"The walks have been killing me this spring," he told the team's official website. "I feel good. I've been throwing the ball hard. I've thrown some real good sinkers."
Zambrano has thrown the ball well at Cincinnati (1-1), going 10-3 with a 3.05 ERA in 17 games there.
While he attempts to start his Marlins career on a positive note in the finale of this three-game set, the club is looking to build on its first win of the young season.
Miami pounded out 12 hits with seven going for extra bases - three homers - in an 8-3 win over Cincinnati on Saturday. That was a vast improvement from the previous two games, when the Marlins totaled seven hits while getting outscored 8-1.
"It's nice to see those guys swinging the bat and building a little confidence," Guillen said.
Giancarlo Stanton went 3 for 5 with a double and three RBIs Saturday after fanning four times, and going 0 for 8 over the previous two games.
The Reds will send Bronson Arroyo to the mound for his season debut after he went 9-12 with a 5.07 ERA last year.
The veteran right-hander won a career-high 17 games in 2010, and showed flashes of that form in his spring-training finale Monday, yielding one run in 6 1-3 innings.
"With all my stuff, I had command of it - the mixture of pitches," Arroyo told the Reds' official website. "It was a little more free and easy. I didn't have to work so hard to feel like I was getting the ball to the plate. Hopefully, that will continue."
Arroyo is 1-3 with a 3.95 ERA in 11 career appearances - eight starts - versus the Marlins.
- Carlos Zambrano
- Ozzie Guillen
- Miami Marlins
- Cincinnati Reds