Over the next month, we're going to present 30 deals in 30 days: The best trade deadline deal ever made by each team.
THE TEAM: Miami Marlins
THE YEAR: 1999
THE SITUATION: The Marlins were on their way to 98 losses, just two seasons after their 1997 World Series triumph. In their rebuilding mode, they were still looking to dump assets for future value and they had hard-throwing 25-year-old reliever Matt Mantei, who had racked up 50 strikeouts in 36.2 innings. On July 8, the Arizona Diamondbacks were 1.5 games out of first place, but veteran closer Gregg Olson had been struggling with 11 saves and six blown saves. They needed an upgrade in the pen.
THE TRADE: The Marlins traded Mantei for minor league pitcher Brad Penny, reliever Vladimir Nunez and a player to be named, minor league outfielder Abraham Nunez. The trade was questioned at the time from the Diamondbacks' perspective, as Penny was viewed as one of the top pitching prospects in the minors (Baseball America had rated him the No. 5 prospect in baseball before the season). Mantei had also missed most of the 1997 with an injury. Abraham Nunez was also a highly regarded prospect and would be ranked No. 30 overall by Baseball America before the 2000 season.
THE AFTERMATH: Mantei assumed the closer role for the Diamondbacks and saved 22 games with a 2.79 ERA the rest of the season as Arizona went on to win the National League West. In Game 4 of the Division Series against the New York Mets, however, Mantei served up the series-losing home run to Todd Pratt. He never was able to remain healthy and missed most of the 2001 season, when Arizona won the World Series. For the Marlins, Nunez never developed, but Penny would win 48 games for them, including two in the 2003 World Series triumph over the New York Yankees. Penny would later be traded to the Los Angeles Dodgers; part of the deal returned reliever Guillermo Mota, who would be part of the Josh Beckett trade with Boston that brought Hanley Ramirez and Anibal Sanchez to the Marlins.