The importance of middle relievers in baseball has increased in recent years, as the trend of starting pitchers failing to go deep into ballgames continues. The Hardball Times provides a graph of the decline in the number of innings pitched by starters over the past hundred years.

With this increased importance, comes a price. In the New York Times, Murray Chase points out that relievers had an average salary of $1,433,992 in 2006 up from $1,316,384 in 2005.

The Mets currently have Pedro Martinez, Oliver Perez, John Maine, and Mike Pelfrey tentatively penciled into their rotation for 2008, with a fifth pitcher likely to come from free agency or via trade this winter. The uncertainty of the Mets rotation makes the need a quality bullpen even greater. The inconsistency of the Mets rotation last season caused the Mets starters to fail to get deep into ballgames, and put a great degree of pressure on an overworked Mets bullpen.

The Mets enter 2008 with a bullpen consisting of Billy Wagner, Scott Schoeneweis, Duaner Sanchez, Jorge Sosa, Pedro Feliciano, Joe Smith, Juan Padilla and possibly Orlando Hernandez.

The Mets will likely use Aaron Heilman as a trading chip to acquire a front line starter.

As we scan the free agent landscape this off season, there are quite a few quality arms available to upgrade with. Two big name closers are on the market, Francisco Cordero and Eric Gange, but will want to close so would be of no use to the Mets.

Ron Mahay, Jeremy Affledt, David Riske, LaTroy Hawkins and Scott Linebrink, Octavio Dotel, and Byung-Hyun Kim are some of the other arms who might be worth a look as middle relievers. Chad Cordero is a longshot, as the Nationals have asked for Carlos Gomez in return and Cordero is also likely to perfer a closing role.

Mahay was 3-0 last year, with a 2.55 ERA and 1.33 WHIP over 67 innings for the Braves. He is considered the best of the middle relievers on the market and has attracted the Yankees interest.

David Riske was 1-4 with a 2.45 ERA and a 1.26 WHIP over 69.7 innings for the Royals. Riske hasn’t had an ERA over 4 since 2002.

Matthew Cerrone on Mets Blog relays information from Mike Pagliarulo who advises the Yankees, who Mark Feinsand of the Daily News said has interest, to steer clear of Linebrink, whose stats indicate a ‘structural decline.’

Octavio Dotel was traded to the Braves from Kansas City at the trade deadline and compiled a 4.11 ERA with a 1.33 WHIP. He spent time on the disabled list with a shoulder strain in August.

The Orioles could look to move Chad Bradford, who is signed to a three year, $10.5 million contract. He compiled a 3.34 ERA with a 1.43 WHIP.