Carlos Zambrano threw so many temper tantrums that he became a headache for the Chicago Cubs. The Marlins are gambling the volatile pitcher will tone down his act — and pile up the victories — with a change of scenery and an understanding manager.

The Marlins and Cubs are swapping starting pitchers, with underachieving Chris Volstad headed to Chicago in exchange for the hot-tempered Zambrano, multiple sources said Wednesday.

The deal is pending the completion of physicals for the pitchers and approval from the commissioner’s office since the Cubs will be picking up $15 million to $16 million of Zambrano’s $18 million salary for next season. The official announcement could come Thursday.

Zambrano, a 30-year-old right-hander, has been a steady winner. In his 11 major-league seasons, all with the Cubs, he has a 125-81 record with a 3.60 earned run average. He finished fifth in the Cy Young Award voting three separate seasons. He is also one of the majors’ top-hitting pitchers.

New Marlins manager Ozzie Guillen lobbied hard for Zambrano, a friend and fellow Venezuelan, just as he did for left-hander Mark Buehrle, another refugee from Chicago who is joining a rotation that already features Josh Johnson, Anibal Sanchez and Ricky Nolasco.

The Marlins are counting on Guillen to keep Zambrano’s emotions in check, no easy assignment given the pitcher’s stormy history. Zambrano has ripped fans, argued with umpires, fumed with teammates and clashed with management. In a fit of anger last August, Zambrano cleaned out his locker after being ejected from a game against Atlanta and informed clubhouse personnel that he was retiring. The Cubs suspended him and docked his pay.

Guillen is confident Zambrano will overcome his emotions and be a winner.

“I got a bet with somebody … he will win a lot of games for the team [next season],” Guillen told reporters last month at the Winter Meetings.

The deal will not cost the Marlins financially.

They will pay Zambrano only what they would have paid Volstad, who is expected to make about $2.5 million in his first year of arbitration.

Volstad never fulfilled his promise with the Marlins, who selected him in the first round (16th overall) of the 2005 amateur draft. The 25-year-old pitcher has struggled since his promising rookie year in 2008 when he went 6-4 with a 2.88 ERA.

Since then, Volstad has gone 26-35 with a 4.86 ERA and has been extremely susceptible to giving up home runs. Last season he was 6-13 and sent to the minors at one point.

The Marlins have already made a splash this offseason with the signings of shortstop Jose Reyes, closer Heath Bell and Buehrle. But they may not be done yet.

They are expected to make a hard push for outfielder Yoenis Cespedes, the 25-year-old outfielder and Cuban defector, once he is granted free agent status.