Closers in waiting: Where will next top fireman come from?

"There's no such thing as a pitching prospect," is a decade-old saying in the sabermetric community meant to indicate, and slightly exaggerate, the volatility of minor league pitching performances, the frequency of pitching injuries, and the extreme risk involved in projecting any young arm for success in the major leagues. While it may not be entirely true that there is "no such thing" as a pitching prospect, it is almost completely true when it comes to closers.

There really is no such thing as a closer prospect. Just look at my list ranking the top closers in the game. Three of the top four (Joe Nathan, Jonathan Papelbon, and Mariano Rivera) debuted in the majors as starting pitchers and have three minor league saves among them. The other, Joakim Soria, came out of nowhere as a Rule 5 pick before he was able to establish prospect status. Francisco Rodriguez was a starter in Class A a year before his big splash in the 2001 postseason.

Bobby Jenks spent five years as a minor league starter before becoming the White Sox's closer in his sixth professional season. Brad Lidge never recorded a minor league save, nor did Kerry Wood, who made 178 major league starts before recording his first save. Jonathan Broxton, Francisco Cordero, Brian Fuentes, Matt Capps, Chad Qualls, Mike Gonzalez, Kevin Gregg, Brad Ziegler, Matt Lindstrom, and Ryan Franklin all began their careers as starting pitchers. Brandon Morrow may still wind up as a starter. The highest-ranking closer on my list who has spent his entire career pitching in relief is 10th-ranked Heath Bell, who is debuting as a closer at 31 after saving 108 minor league games and spending a handful of big league seasons as a middle reliever.

The A's seemed to discover a new source of closing talent when they drafted University of Texas closer Huston Street in June 2004 and installed him in the major league bullpen the following April. When Octavio Dotel went under the knife for Tommy John surgery, Street took over the closer job and went on to win the 2005 American League Rookie of the Year award. The Red Sox and Yankees attempted to repeat the formula of drafting nearly major league-ready college closers that June when they took Craig Hansen of St. John's and Street's Longhorn successor J.B. Cox, respectively, but Hansen didn't respond well to being rushed to the majors, and Cox now seems unlikely to ever make The Show. Meanwhile, the A's soured on Street as he blew 23 saves in the three years that followed his Rookie of the Year campaign. So much for that idea.

Because minor league closers so rarely become major league closers, it's difficult to identify the next superstar at the position before he emerges either seemingly out of the ether, like Soria or K-Rod, or by shedding the skin of failed starter, like Rivera, Nathan, or Jenks. That said, there are a few compelling closers in waiting on major league rosters right now. The most obvious is Carlos Marmol, another former starter who never saved a game in the minors. By all rights, Marmol should already be the Cubs' closer given his performance as a setup man the past two years (2.13 ERA, 1.00 WHIP, 12.1 K/9). Joel Zumaya, again a former starter who never saved a minor league game, has been in Marmol's position for the Tigers since 2006, but has had his path to the closer job interrupted by various injuries. Finally back on the mound, Zumaya and his triple-digit heat could wind up stealing the job from Fernando Rodney before the year is out. In St. Louis, veteran journeyman Ryan Franklin is keeping the job warm for one of two real-life closer prospects, 27-year-old Jason Motte and 23-year-old Chris Perez. It took Motte all of one save opportunity to cough up the job he earned in spring training, but that's partially because Perez is the pitcher the Cardinals hope will ultimately secure the job. Since being drafted in the first supplemental round in 2006, Perez has posted a 2.72 ERA and 12.1 K/9 in the minors while saving 58 games in parts of three seasons.

In the minors, there are two pitchers who stand out as potential star closers. Distressingly for the rest of the American League, one belongs to the Red Sox, giving them an embarrassment of riches at the position. The Sox drafted Texan righty Daniel Bard as a starter (of course) out of the University of North Carolina with the 28th overall pick in the 2006 draft. Bard moved to the bullpen last year and tore through A-ball and Double-A. This year, he's making quick work of the International league at age 23, currently boasting a 1.23 ERA, 0.68 WHIP, 15.3 K/9, and 5.0 K/BB as the closer for Triple-A Pawtucket. Down in High-A, the Mariners have a potential fast-mover who could replace Morrow if the M's decide to move Morrow back into the rotation. The 11th-overall pick in the 2007 draft, 6-foot-7 Quebecois lefty Phillipe Aumont, also drafted as a starter, has a down-sloping high-90s heater that opposing batters either beat into the ground or miss completely. After making eight starts last year, Aumont pitched in relief for Team Canada in the World Baseball Classic and has remained in the pen for the High Desert Mavericks, posting a 0.73 ERA over his first 12 appearances this season.

As for where the other future closers might come from, look no further than the top starting prospects in the game, as relief stints by Joba Chamberlain and David Price have certainly whet the appetites of some both in and out of the Yankees and Rays organizations, respectively.

Closers could emerge from the All-Star scrap heap. Ben Sheets, for example, would be a prime candidate to follow Wood's lead as an often dominant starter who has proven unable to stay healthy. They could come almost instantly out of the Japanese, Mexican, or independent leagues, as Takashi Saito, Soria, and Ziegler have done in recent years. Or maybe the top closer five years from now is currently a weak-hitting rookie-ball catcher or infielder with a strong arm, as was the case with Troy Percival and Trevor Hoffman.

Closers are an odd group. Despite the old stereotype of fire-breathing, mustachioed madmen stomping about on the mound, most closers today are made, not bred, and they're typically made at the major league level. Much like Mariano Rivera in 1995, the next great closer may actually have been the otherwise unimpressive spot-starter or middle reliever you watched pitch last night. I hope you were paying attention.

MORE COVERAGE

Corcoran:Closer rankings, from No. 1 to 30Verducci:Ranking the 10 best closers everReact:How do you rank today's closers? All time?Corcoran:How role of relief ace has changedAschburner:Twins' Nathan is unsung -- just how he likes itKeith:Bell filling Hoffman's shoes nicely in San Diego