MIAMI -- Finishing in last place in the National League East prompted the Marlins to make major changes.

The organization did just that on Monday, officially announcing a mega-trade with Toronto that was agreed upon last Tuesday night.

Miami is parting with established veterans Josh Johnson, Mark Buehrle, Jose Reyes, Emilio Bonifacio and John Buck. In return, the club is receiving Yunel Escobar, Adeiny Hechavarria, Henderson Alvarez, Justin Nicolino, Jeff Mathis, Jake Marisnick and Anthony DeSclafani.

"We've finished in last place the past two years, and that is unacceptable to our fans, to us as an organization, and to me," Marlins owner Jeffrey Loria said. "We want to get back to our winning ways, and we want a winning baseball team for our fans. It's incumbent on us to make the changes necessary to make us a winner again.

"It may not happen overnight. But with the players we acquired in the second half of last season, coupled with the infusion of players we are acquiring now, we will be returning to Marlins Baseball: high energy and hungry."

In their 20-year history, the Marlins certainly have made significant deals. Until now, none included as many as 12 players, making it the largest transaction in franchise history.

"I think it's part of the organizational underachievement," Miami president of baseball operations Larry Beinfest said. "I think on the field we found a way to underachieve. I think in the front office, either through decision-making or evaluation, we found a way to underachieve. There was not a comfortable level, moving forward, that we had the pieces here as currently constituted to put together a championship club."

The Blue Jays added experience and four players who have been to at least one All-Star Game. They're being talked about as a playoff contender in the American League. In Miami, the deal has been upsetting to some among the Marlins' fan base, prompting Miami Mayor Tomas Regalado to write a letter to Major League Baseball Commissioner Bud Selig to closely examine the reasoning for the transaction.

"Since Tuesday, I have carefully reviewed the proposed transaction between the Miami Marlins and the Toronto Blue Jays," Selig said. "I asked our baseball operations department and our labor relations department to compare this proposed transaction with similar deals. I also consulted with experienced baseball operations executives to get their input regarding the talent involved in this transaction.

"After a thorough examination of this information, it is my conclusion that this transaction, involving established Major Leaguers and highly regarded young players and prospects, represents the exercise of plausible baseball judgment on the part of both clubs, does not violate any express rule of Major League Baseball and does not otherwise warrant the exercise of any of my powers to prevent its completion."

By dealing five of their regulars, the Marlins cleared nearly $160 million in base salaries off their books. The root of the disappointment presumably stems from the club's change of direction after its first season at Marlins Park.

"It is, of course, up to the clubs involved to make the case to their respective fans that this transaction makes sense and enhances the competitive position of each, now or in the future," Selig said. "I am sensitive to the concerns of the fans of Miami regarding this trade, and I understand the reactions I have heard since Tuesday. Baseball is a social institution with important social responsibilities, and I fully understand that the Miami community has done its part to put the Marlins into a position to succeed with beautiful new Marlins Park.

"Going forward, I will continue to monitor this situation with the expectation that the Marlins will take into account the sentiments of their fans, who deserve the best efforts and considered judgment of their club. I have received assurances from the ownership of the Marlins that they share these beliefs and are fully committed to build a long-term winning team that their fans can be proud of."

Moving into a new ballpark, with additional revenue streams, was seen as a beginning where the Marlins would be able to increase payroll. Beinfest acknowledged that trimming payroll was a factor, as the front office was given a scaled-down range with which to work. Although a specific payroll was not revealed, it projects to be in the $40 million range.

Fitting into their budget is veteran outfielder Juan Pierre, who officially signed a one-year, $1.6 million contract with Miami on Monday.

"We did receive a payroll range from ownership that we needed to achieve," Beinfest said. "And with this transaction, we have achieved that payroll range, including the Juan Pierre signing. We are in that payroll range and are prepared to move forward with some very good young players we did receive from the Blue Jays, coupled with the players we received last summer and hopefully some additional moves we make this offseason as we get ready for 2013."

The Marlins had great expectations in 2012, sporting a club-record payroll of $101 million and featuring a number of high-profile players like Reyes and Hanley Ramirez. But after struggling for most of the first half, the club made three trades in late July, parting with Ramirez, Anibal Sanchez, Omar Infante, Randy Choate, Edward Mujica and Gaby Sanchez.

Losing veteran players to trade and injury contributed to the team finishing last in the NL East with a 69-93 record. Three weeks after the season ended, the transformation began with the dismissal of outspoken manager Ozzie Guillen.

When Mike Redmond, two years removed from his playing days, was named manager on Nov. 1, it was a sign the team was redirecting to get younger. More changes were forecast, but few envisioned the deals would reach Reyes and Buehrle, two major free-agent pickups who were sold as building blocks for several seasons in Miami.

A year ago, the Marlins were the talk of the Winter Meetings, boasting the free-agent signings of Reyes, Buehrle and Heath Bell. Their big three fit into the team's rebranding and were seen as signals that the organization was primed to challenge the big markets on the spending front.

But less than a year later, all three have been traded. Bell, who struggled and lost his closer's role after the All-Star break, was dealt to the D-backs a few weeks ago.

"I think the fans are disappointed with the baseball we played last summer, regardless of the moves that we've made since then," Beinfest said. "We didn't play well. And yes, we had some very recognizable names, and they are good players. There's no question about it. I'd be the last person to assign blame to any one person in this organization, whether it was a manager, a coach, a player, or a front-office [person] to contribute to this. Somehow, we found a way, with the all-in approach, etc., to not get it done.

"I think the fans have every right to be concerned. I think they can be disappointed in the way that we played. I think they can be hopeful that we've done our job and that we're going to get better. That's what this is all about. This is about getting better. This isn't about payroll."

Since July, the Marlins have traded 12 players who were on their Opening Day roster. The organization maintains the moves were mandated by the fact the big-name roster didn't generate enough wins.

By comparison, the Marlins finished 72-90 with a $57 million payroll in 2011.

Losing 93 games, the team contends, was unacceptable and triggered a transformation.

From the trade, at least four of the new players project to be on the Marlins' Opening Day roster -- Escobar, Hechavarria, Alvarez and Mathis.

Escobar, 30, has been a shortstop for much of his career, but Miami sees him as a third baseman. The 30-year-old was involved in some controversy last season with Toronto, as he was suspended for three games for displaying a gay slur on his eye black. He later apologized and said he agreed with the disciplinary actions.

Hechavarria is expected to replace Reyes at shortstop. The 23-year-old Cuba native is terrific defensively, but he has played just 41 games in the big leagues. He batted .254, and there are questions about how much he is going to hit.

Alvarez, 22, is a Venezuela native who will factor into Miami's rotation. The right-hander made 31 starts last year, posting a 9-14 record and a 4.85 ERA in 187 1/3 innings.

Mathis, 29, broke into the big leagues with the Angels in 2005, and he should replace Buck as Miami's backup catcher to Rob Brantly.

Marisnick is a five-tool-caliber outfielder. According to MLB.com's Jonathan Mayo, the 21-year-old was the Blue Jays' No. 2 overall prospect. He played for Redmond in Class A Dunedin at the start of the year, and was promoted to Double-A.

Nicolino, who turns 21 on Thanksgiving, is a left-hander who went 10-4 with a 2.46 ERA and 119 strikeouts in 124 1/3 innings at Class A Lansing. DeSclafani, a right-hander, was a teammate of Nicolino in Lansing, and he was 11-3 with a 3.37 ERA, striking out 92 in 123 innings.

Prior to pulling off the deal with the Jays, the largest trade the Marlins made involved 11 players. It came on July 11, 2002, as part of a three-team deal. The Marlins dealt Ryan Dempster that day to the Reds for Juan Encarnacion, Wilton Guerrero and Ryan Snare. They then traded Cliff Floyd, Guerrero and Claudio Vargas to Montreal for Graeme Lloyd, Mike Mordecai, Carl Pavano, Justin Wayne and Don Levinski (a player to be named).

Had the Marlins decided to keep Reyes and Buehrle, the feeling in the organization is that with payroll parameters, it was unlikely they would be surrounded by enough talent to advance the team significantly forward.

"We were very high-profile," Beinfest said of the Marlins' major signings a year ago. "We were very out front with what we were doing. We knew exactly what we were doing. Did we make great decisions all the way around? Probably not.

"Reyes and Buehrle, no doubt. They made a commitment here. We made a commitment to them. It just didn't work out. That's where we're at. It's not an indictment of Jose or Mark. I don't think you can find two better people in the game or guys who work harder or want to win more. It just didn't work out. We needed to hit the reset.

"If we had kept those two specifically, did we have enough around them to make a go at it, given some of the payroll direction we were heading? The answer was no. So we made a tough decision. I wouldn't expect them to be happy. We're not happy about it. I don't think anybody is happy about it here. But we dealt with the situation and we're moving forward."