Ozzie Guillen headed to the airport Monday evening for a six-hour flight — plenty of time to decide how to shake up his slumping team.

The Miami Marlins fell deeper into last place in the NL East with a 9-5 loss Monday afternoon to the Arizona Diamondbacks, and Guillen said something needs to change.

It might be the lineup. Guillen criticized his players' failure to change their approach at the plate or on the mound.

"If you cannot make an adjustment, I will make it for you," he said. "I'm going to make a very drastic change. I don't know which one yet, but I'm going to make an adjustment. I'm pretty good at that. That's my job."

The Marlins have lost eight of their past nine games, and the latest defeat was galling because it came against Arizona's Patrick Corbin, making his major-league debut.

One day after falling behind 8-0, the Marlins trailed 7-0 by the fifth inning. Fans booed for the second game in a row.

"Can you blame them?" Guillen said. "I was booing, too. It's a shame, because we've got a better ballclub than we've showed. The last couple of games, things got out of hand — very lousy baseball, period."

The Marlins, expected to contend for a division title after an offseason spending spree, are 8-14 as they begin a nine-game trip Tuesday in San Francisco.

"We are too good to continue to play the way were playing right now," shortstop Jose Reyes said. "We need to turn it around quickly."

The 22-year-old Corbin, a left-hander called up from Double-A Mobile, struck out six and allowed three runs in 5 2-3 innings. Cody Ransom and Justin Upton hit two-run homers for Arizona, and Willie Bloomquist had a two-run double.

Miami tapped into a 1-2-3 bases-loaded double play and committed three errors, including one on a misplayed bunt that led to a five-run inning.

Mark Buehrle (1-4) endured his worst outing this season. Facing Arizona for the first time in his 370th career start, the left-hander lasted only five innings and allowed seven runs — four earned — and eight hits.

"I guess it could get worse," Buehrle said. "We won eight games this month. We could have won none. We've got to keep going at it."

Struggling closer Heath Bell gave up two runs in a non-save situation in the ninth. His ERA rose to 10.80.

"Everybody knows he has struggled," Guillen said. "Everybody knows he has a lot of problems. Make an adjustment, and hopefully it can work."

After the Marlins threatened in the first inning, they didn't manage another hit off Corbin until the fifth, when John Buck singled and pinch-hitter Donnie Murphy homered.

Miami's Austin Kearns hit a two-run homer in the seventh.

"At least we fought back," Reyes said. "We put some runs on the scoreboard. That's good. But still we lost the game. It's kind of disappointing for us, because we're better than this."

The Marlins fell to 2-6 against left-handers with a batting average of .188.

Thanks to the retractable roof on the Marlins' new ballpark, a rainout may have been averted for a second day in a row. Announced attendance was 31,008, and the afternoon crowd included 12,000 schoolchildren who generated a high-pitched din throughout the game.

There were jeers from the adults in the crowd during Arizona's five-run fourth inning.

"I'd be booing us too, the way we're playing," Buehrle said.

NOTES: LHP Dan Jennings was in Triple-A and planning to attend a wedding shower with his fiancee this week in Iowa, but those plans were put on hold when he was called up to the majors for the first time. He joined the Marlins before the game and pitched a hitless sixth. ... Marlins attendance topped 30,000 for the eighth time in 11 home games.